thermodynamics (-dai næm´iks) •n.pl. [with sing. v.] the branch of physics dealing with the transformation of heat to and from other forms of energy, and with the laws governing such conversions of energy [THERMO- + DYNAMICS]

thermoelectric (-i: lek´trik) •adj. of or having to do with the direct relations between heat and electricity Also ther'mo·e·lec´tri·cal ther'mo·e·lec´tri·cal·ly •adv.

thermoelectricity (-i:'lek tris´э ti:) •n. electricity produced by heating or cooling one junction of a thermocouple so as to produce an electromotive force

thermoelectromotive (θør'mou i: lek'trэ mout´iv) •adj. designating or of the electromotive force produced by a thermocouple

thermoelectron (-i: lek´trän') •n. a negative ion, or electron, emitted from a body at high temperature

thermoelement (-el´э mэnt) •n. a device consisting of a thermocouple and a heating element arranged for measuring small currents, esp. at high frequencies

thermogenesis (-jen´э sis) •n. the production of heat, esp. by physiological action in an animal ther'mo·ge·net´ic (-jэ net´ik) •adj. [ModL: see THERMO- & -GENESIS]

thermogram (θør´mou græm', -mэ-) •n. a record made by a thermograph [THERMO- + -GRAM]

thermograph (-græf') •n. a thermometer for recording variations in temperature automatically; specif., an infrared camera for recording on film or on the face of an oscilloscope differences in temperature, as between normal and abnormal body tissues [THERMO- + -GRAPH]

thermography (θэr mäg´rэ fi:) •n. 1 the recording of temperature variations by means of a thermograph 2 a process for imitating copperplate engraving, as on calling cards, by dusting the freshly printed surface with a resinous powder which, when heated, fuses with the ink to form a raised surface ther·mog´ra·pher •n. ther·mo·graph·ic (θør'mэ græf´ik) •adj. [THERMO- + -GRAPHY]

thermojunction (θør'mou jûŋk´shэn) •n. the point of contact between the two conductors forming a thermocouple

thermolabile (-lei´bэl) •adj. designating or of substances, as some toxins, enzymes, etc., that are destroyed or lose their characteristic properties when subjected to heat, esp. to a temperature of 55°C (131°F) or above ther'mo·la·bil´i·ty (-lei bil´э ti:) •n. [THERMO- + LABILE]

thermoluminescence (-lu:'mэ nes´эns) •n. the release in the form of light of stored energy from a substance when it is heated ther'mo·lu'mi·nes´cent •adj. [THERMO- + LUMINESCENCE]

thermolysis (θэr mäl´э sis) •n. 1 Chem. dissociation of a compound by heat 2 Physiol. dispersion of heat from the body ther'mo·lyt´ic (-mou lit´ik) •adj. [ModL: see THERMO- & -LYSIS]

thermomagnetic (θør'mou mæg net´ik) •adj. of or pertaining to the interrelations between heat and magnetism

thermometer (θэr mäm´эt эr) •n. 1 an instrument for measuring temperatures, consisting of a graduated glass tube with a sealed, capillary bore in which mercury, colored alcohol, etc. rises or falls as it expands or contracts from changes in temperature: see FAHRENHEIT, CELSIUS, KELVIN, REAUMUR 2 any similar instrument, as one operating by means of a thermocouple ther·mo·met·ric (θør'mou met´rik) •adj. ther'mo·met´ri·cal·ly •adv. [Fr thermomètre: see THERMO- & -METER]

thermometry (-э tri:) •n. 1 measurement of temperature 2 the science of making or using thermometers

thermomotor (θør'mou mout´эr) •n. an engine operated by heat, esp. by the expansion of heated air

thermonuclear (θør'mou nu:´kli: эr, -nyu:´-) •adj. Physics 1 designating or of a reaction in which isotopes of a light element, esp. hydrogen, fuse at temperatures of millions of degrees into heavier nuclei 2 designating, of, or employing the heat energy released in nuclear fusion {thermonuclear reactor} [THERMO- + NUCLEAR]

thermophile (θør´mou fail') •n. an organism adapted to living at high temperatures, as some bacteria and algae ther'mo·phil´ic (-fil´ik) •adj. [THERMO- + -PHILE]

thermopile (-pail') •n. a device consisting of a series of thermocouples, used for measuring minute changes in temperature or for generating thermoelectric current [THERMO- + PILE¹]

thermoplastic (θør'mou plæs´tik) •adj. becoming or remaining soft and moldable when subjected to heat: said of certain plastics •n. a thermoplastic substance

Thermopylae (θэr mäp´э li:') in ancient Greece, a mountain pass in Locris, near an inlet of the Aegean Sea: scene of a battle (480 B.C.) in which the Persians under Xerxes destroyed a Spartan army under Leonidas

thermoregulation (θør'mou reg'yu: lei´shэn) •n. 1 the regulation of temperature 2 Physiol. the keeping of the temperature of a living body at a constant level by processes of heat production, heat transport, etc. ther'mo·reg´u·la'tor •n.

thermos (θør´mэs) •n. a bottle, flask, or jug for keeping liquids at almost their original temperature for several hours: it has two walls enclosing a vacuum and is fitted in a metal outer case: in full thermos bottle (or flask or jug) [orig. a trademark < Gr thermos, hot, WARM]

thermoscope (θør´mou skoup', -mэ-) •n. an instrument for indicating changes in temperature of a substance, without accurately measuring them, by observing the accompanying changes in volume ther'mo·scop´ic (-skäp´ik) •adj. [THERMO- + -SCOPE]

thermosetting (θør´mou set'iŋ) •adj. becoming permanently hard and rigid when once subjected to heat: said of certain plastics

thermosiphon (θør'mou sai´fэn) •n. an apparatus consisting of an arrangement of siphon tubes for inducing the circulation of a liquid, as in the water-cooling system of an internal-combustion engine

thermosphere (θør´mou sfir') •n. the atmospheric zone or shell located above the mesopause beginning at an altitude of c. 85 km (53 mi.) and characterized by a great rise in temperature with increasing altitude See IONOSPHERE, EXOSPHERE

thermostable (θør'mou stei´bэl) •adj. designating or of substances, as some toxins, enzymes, etc., that can be heated to moderate temperatures above 55°C (131°F) without losing their characteristic properties ther'mo·sta·bil´i·ty (-stэ bil´э ti:) •n. [THERMO- + STABLE¹]

thermostat (θør´mэ stæt') •n. 1 an apparatus for regulating temperature, esp. one that automatically controls a heating or cooling unit 2 a device that sets off equipment at a certain temperature, as a fire alarm system ther'mo·stat´ic •adj. ther'mo·stat´i·cal·ly •adv. [THERMO- + -STAT]

thermostatics (θør'mou stæt´iks, -mэ-) •n.pl. [with sing. v.] the science that deals with the equilibrium of heat [THERMO- + STATICS]

thermotaxis (-tæk´sis) •n. 1 Biol. the positive, or negative, response of a freely moving organism toward, or away from, a source of heat 2 Physiol. the normal regulation of body temperature ther'mo·tax´ic or ther'mo·tac´tic (-tik) •adj. [ModL: see THERMO- & -TAXIS]

thermotensile (-ten´sil) •adj. of or having a tensile strength that varies with changes in temperature

thermotropism (θэr mä´trэ piz¿эm) •n. Biol. any positive, or negative, movement or growth of a plant or sessile animal toward, or away from, a source of heat ther·mo·trop·ic (θør'mou träp´ik) •adj. [THERMO- + -TROPISM]

theroid (θir´oid') •adj. suggestive of an animal; beastlike [Gr thēr, a wild beast (see FIERCE) + -OID]

theropod (θir´э päd') •n. any of a suborder (Theropoda, order Saurischia) of flesh-eating dinosaurs that walked mainly on the hind legs [< ModL Theropoda < Gr thēr, a wild beast (see FIERCE) + -PODA]

Thersites (θэr sait´i:z') in the Iliad, an ugly, loud, abusive Greek soldier in the Trojan War [L < Gr Thersitēs < dial. (Lesbian) thersos, boldness, for tharsos: see THRASONICAL]

thersitical (θэr sit´i kэl) •adj. loud and abusive [after prec.]

Thes Thessalonians

thesaurus (θi sö´rэs) pl. -sau´ri' (-rai') or -sau´rus·es •n. 1 a treasury or storehouse 2 a book containing a store of words; specif., a book of synonyms and antonyms 3 a categorized index of terms for use in information retrieval, as from a computer [L < Gr thēsauros, a treasure]

these (ði:z) pron., adj. pl. of THIS

Theseus (θe´si: эs) Gr. Legend the principal hero of Attica, son of Aegeus and king of Athens, famed esp. for his killing of the Minotaur The·se·an (θi: si:´эn) •adj. [L < Gr Thēseus]

thesis (θi:´sis) pl. the´ses' (-si:z') •n. 1 a) in classical Greek poetry, the long syllable of a foot b) in later poetry, the short or unaccented syllable or syllables of a foot 2 a proposition maintained or defended in argument, formerly one publicly disputed by a candidate for a degree in a medieval university 3 a formal and lengthy research paper, esp. a work of original research written in partial fulfillment of the requirements for a master's degree: see DISSERTATION 4 an unproved statement assumed as a premise 5 in Hegelian philosophy, the initial, least adequate phase of development in dialectic: see DIALECTIC (n. 3) [L < Gr, a placing, position, proposition < base of tithenai, to put, place: see DO¹]

Thespian (θes´pi: эn) •adj. 1 of Thespis 2 [often t-] having to do with the drama; dramatic •n. [often t-] an actor or actress: a somewhat humorous or pretentious term

Thespis (θes´pis) 6th cent. B.C.; Gr. poet: traditionally the originator of Gr. tragedy

Thess Thessalonians

Thessalia (θэ seil´yэ; θe'sэ li:´э) Gr. name of THESSALY

Thessalonian (θes'э lou´ni: эn) •adj. of Thessalonica or its people •n. a native or inhabitant of Thessalonica

Thessalonians (-эnz) either of two books of the New Testament which were letters from the Apostle Paul to the Christians of Thessalonica Abbrev. Thess, Thes, or Th

Thessalonica (θes'э län´i kэ, -э lou nai´kэ) ancient name of SALONIKA

Thessaloniki or Thessalonike (θes'ä lö'ni:´ki:) Gr. name of SALONIKA

Thessaly (θes´э li:) region of E Greece, between the Pindus Mountains & the Aegean Sea: see GREECE, map Thes·sa·li·an (θэ sæl´yэn, -sei´li: эn) •adj., n.

theta (θeit´э, θi:t´-) name of the eighth letter of the Greek alphabet (Θ, ##, θ) •n. [Gr thēta: of Sem orig., akin to Heb tet]

theta wave any of the electrical brain waves having a frequency between four and eight hertz and associated with a drowsy, semiconscious state of mind: also theta rhythm

thetic (θet´ik) •adj. set forth dogmatically; prescribed: also thet´i·cal thet´i·cal·ly •adv. [Gr thetikos, fit for placing < thetos, placed < base of tithenai: see DO¹]

Thetis (θi:t´is) Gr. Myth. one of the Nereids and mother of Achilles [L < Gr Thetis]

theurgy (θi:´эr ji:, -ør'-) pl. -gies •n. 1 an occurrence or accomplishment or a sequence of these, esp. when remarkable or extraordinary, viewed as effected by supernatural or divine agency 2 a set of acts or incantations taken to be capable of producing such occurrences or accomplishments the·ur·gic (θi: ør´jik) or the·ur´gi·cal •adj. the·ur´gi·cal·ly •adv. the´ur·gist •n. [LL(Ec) theurgia, a summoning of spirits < LGr(Ec) theourgia < theourgos, divine worker < Gr theos, god (see THEO-) + ergon, WORK]

thewless (θyu:´lis) •adj. [Chiefly Scot.] without vigor or spirit

thews (θyu:z) sing. thew •n.pl. 1 muscular power; bodily strength 2 muscles or sinews thew´y, thew´i·er, thew´i·est, •adj. [ME theawes, good qualities, hence, later, good physical qualities, strength < OE theaw, custom, habit, hence characteristic quality, akin to OS thau, custom < IE base *teu-, to pay attention to, notice > L tueri, to keep in sight, observe]

they (ðei) sing. he, she, or it pron. 1 the persons, animals, or things previously mentioned: also used with a singular antecedent (as everybody, somebody, everyone) {everyone helped, and it was good that they did} 2 people (or a person) generally or indefinitely {they say it's so} They is the nominative case form, them the objective, their and theirs the possessive, and themselves the intensive and reflexive, of the third personal plural pronoun [ME thei < ON thei-r, nom. masc. pl. of the demonstrative pron.; like THEIR & THEM (ME theim), also < the ON demonstrative forms, thei replaced earlier ME he (hi) because the native pronouns were phonetically confused with the forms of the pers. pron. (ME he, hire, hem, him, etc.): cf. THEIR, THEM, SHE]

they'd (ðeid) 1 they had 2 they would

they'll (ðeil, ðel) 1 they will 2 they shall

they're (ðer, ðei´эr) they are

they've (ðeiv) they have

thi- (θai) combining form THIO-

thiamine (θai´э mi:n', -min) •n. a white, crystalline B vitamin, C12H17ClN4OS, found in the outer coating of cereal grains, green peas, beans, egg yolk, liver, etc., and also prepared synthetically; vitamin B1: a deficiency of this vitamin results in beriberi and certain nervous disorders: also thi´a·min (-min) [< prec. + (VIT)AMIN]

thiazine (θai´э zi:n', -zin) •n. any of a group of heterocyclic compounds whose molecules contain one atom of nitrogen, one atom of sulfur, and four atoms of carbon, arranged in a ring [THI- + AZINE]

thiazole (θai´э zoul') •n. 1 a colorless liquid, C3H3NS, with a five-membered ring 2 any of its various derivatives, used in dyes and drugs [THI- + AZOLE]

Thibet (tэ bet´) alt. sp. of TIBET Thi·bet´an •adj., n.

thick (θik) •adj. 1 having relatively great depth; of considerable extent from one surface or side to the opposite; not thin {a thick board} 2 having relatively large diameter in relation to length {a thick pipe} 3 as measured in the third dimension or between opposite surfaces {a wall six inches thick} 4 having the constituent elements abundant and close together; specif., a) marked by profuse, close growth; luxuriant {thick hair, thick woods} b) great in number and packed closely together {a thick crowd} c) having much body; not thin in consistency; viscous {thick soup} d) dense and heavy {thick smoke, a thick snowfall} e) filled with smoke, fog, or other vapors f) covered to a considerable depth {roads thick with mud} g) sprinkled or studded profusely {a sky thick with stars} 5 impenetrably dark, dismal, or obscure {the thick shadows of night} 6 a) sounding blurred, slurred, muffled, fuzzy, etc., or husky, hoarse, etc. {a thick voice, thick speech} b) strongly marked; pronounced {speaking with a thick brogue} 7 [Colloq.] slow to understand; stupid 8 [Colloq.] close in friendly association; intimate 9 [Colloq., Chiefly Brit., etc.] too much to be tolerated; excessive •adv. in a thick way •n. the thickest part or the period of greatest activity {in the thick of the fight} SYN. CLOSE¹ through thick and thin in good times and bad times; in every eventuality thick´ish •adj. thick´ly •adv. [ME thikke < OE thicce, thick, dense, akin to Ger dick < IE base *tegu-, thick, fat > OIr tiug]

thicken (θik´эn) •vt., vi. 1 to make or become thick or thicker, as in dimension, density, consistency, articulation, etc. 2 to make or become more complex or involved {the plot thickened} thick´en·er •n.

thickening (θik´эn iŋ) •n. 1 the action of a person or thing that thickens 2 a substance or material used to thicken 3 the thickened part of something

thicket (θik´it) •n. a thick growth of shrubs, underbrush, or small trees thick´et·ed •adj. [ME < OE thiccet < thicce, THICK]

thickhead (θik´hed') •n. a stupid person; blockhead thick´head'ed •adj. thick´head'ed·ness •n.

thickness (θik´nis) •n. 1 the quality or condition of being thick 2 the measure of how thick a thing is, as distinguished from the length or width of any of its surfaces 3 a layer, stratum, etc. {three thicknesses of cloth} 4 the thickest place or part

thickset (θik´set') •adj. 1 planted thickly or closely 2 thick in body; stocky •n. [Archaic] a thicket

thick-skinned (θik´skind') •adj. 1 having a thick skin 2 not easily hurt by criticism, insult, etc.; callous

thick-skulled (θik´skûld') •adj. stupid or obtuse

thick-witted (θik´wit'id) •adj. slow-witted; stupid

thief (θi:f) pl. thieves (θi:vz) •n. a person who steals, esp. secretly; one guilty of theft, or larceny [ME < OE theof, thiof, akin to Ger dieb < IE base *teup-, to cower, lurk]

Thiers (tyeř), Louis A·dolphe (lwi: å dôlf´) 1797-1877; Fr. statesman & historian

thieve (θi:v) thieved, thiev´ing •vt., vi. to commit, or get by, theft [via ME dial. < OE theofian < theof, THIEF]

thievery (θi:v´эr i:) pl. -er·ies •n. the act or practice of stealing or an instance of this; theft

thievish (θi:v´ish) •adj. 1 addicted to thieving, or stealing 2 of, like, or characteristic of a thief; stealthy; furtive thiev´ish·ly •adv. thiev´ish·ness •n.

thigh (θai) •n. 1 that part of the leg in humans and other vertebrates between the knee and the hip; region of the thighbone, or femur 2 the region of the tibia, as in poultry [ME thih < OE theoh, akin to MHG diech < IE *teuk- < base *teu-, to swell > THUMB, L tumor]

thighbone (θai´boun') •n. FEMUR: also thigh bone

thigmotaxis (θig'mou tæks´is) •n. STEREOTAXIS thig'mo·tac´tic (-tæk´tik) •adj. [ModL < Gr thigma, touch < thinganein, to touch with the hand (< IE base *dheiGh-, to knead > DOUGH) + -taxis, -TAXIS]

thigmotropism (θig mä´trэ piz'эm) •n. STEREOTROPISM thig'mo·trop´ic (-mou träp´ik) •adj. [ModL: see THIGMOTAXIS & -TROPISM]

thill (θil) •n. either of the two shafts between which a horse is hitched to a wagon [ME thille, a stake, pole, plank < OE, akin to ON thil, OHG dil, board wall, plank floor < IE base *telo-, flat surface > L tellus, earth]

thimble (θim´bэl) •n. 1 a small cap of metal, plastic, etc. worn as a protection on the finger that pushes the needle in sewing 2 anything like this; esp., a grooved, metal ring inserted in a loop of rope or in a sail's rope hole to prevent wear [ME thimbel (with unhistoric -b-) < OE thymel, thumbstall < thuma, THUMB + -el, dim. suffix]

thimbleberry (θim´bэl ber'i:) pl. -ries •n. BLACK RASPBERRY

thimbleful (θim´bэl ful') pl. -fuls' •n. 1 as much as a thimble will hold 2 a very small quantity

thimblerig (θim´bэl rig') •n. SHELL GAME •vt., vi. -rigged', -rig'ging to cheat or swindle, as in this game thim´ble·rig'ger •n. [see RIG]

thimbleweed (θim´bэl wi:d') •n. any of various plants with thimble-shaped receptacles; esp., a) any of several anemones with elongated cylindrical heads of woolly achenes b) any of several rudbeckias

thimerosal (θai mer´э sæl', -mør´-) •n. a cream-colored, crystalline compound, C9H9HgNaO2S, used chiefly in solutions as an antiseptic for surface wounds [by contr. and transposition of (sodium ethyl)mercurithiosalicylate, the name of the compound]

thin (θin) thin´ner, thin´nest •adj. 1 having relatively little depth; of little extent from one surface or side to the opposite {thin paper} 2 having relatively small diameter in relation to length {thin thread} 3 having little fat or flesh; lean; gaunt; slender 4 having the constituent elements small in number and not close together; specif., a) scanty in growth; sparsely distributed {thin hair} b) small in size or number {thin receipts} c) lacking body; not thick in consistency; watery {thin soup} d) not dense or heavy {thin smoke, a thin snowfall} e) rarefied, as air at high altitudes 5 of little intensity; dim; faint; pale {thin colors} 6 of little volume or resonance; high-pitched and weak {a thin voice} 7 light or sheer, as fabric 8 easily seen through; flimsy or unconvincing {a thin excuse} 9 lacking solidity, substance, or vigor; slight, weak, vapid, etc. {a thin plot, thin argument} 10 Photog. lacking in DENSITY (sense 1c): said of an underexposed or underdeveloped negative or print •adv. in a thin way •vt., vi. thinned, thin´ning to make or become thin or thinner, as in dimension, density, etc. Often with out, down, etc. [ME thinnen < OE (ge)thynnian < the adj.] thin´ly •adv. thin´ness •n. [ME thinne < OE thynne, akin to Ger dünn < IE *tenu-, thin < base *ten-, to stretch > L tenuis, thin, tenere, to hold, tendere & Gr teinein, to stretch]

thine (ðain) pron. [Archaic] that or those belonging to thee (you): absolute form of THY {a friend of thine, this is thine} possessive pronominal adj. [Archaic] thy: used esp. before a word beginning with a vowel or unaspirated h [ME thin < OE, gen. of thu, THOU¹ (ME loss of -n before a consonant gives THY)]

thing (tiŋ; E θiŋ) •n. a Scandinavian legislative body [ON, assembly: see THING] thing (θiŋ) •n. 1 any matter, circumstance, affair, or concern: often used in pl. {how are things?} 2 that which is done, has been done, or is to be done; happening, act, deed, incident, event, etc. {to accomplish great things} 3 that which constitutes an end to be achieved, a step in a process, etc. {the next thing is to mix thoroughly} 4 anything conceived of or referred to as existing as an individual, distinguishable entity; specif., a) any single entity distinguished from all others {each thing in the universe} b) a tangible object, as distinguished from a concept, quality, etc. {paintings and other beautiful things} c) an inanimate object d) an item, detail, etc. {go over each thing in the list} e) the object or concept referred to or represented by a word, symbol, or sign; referent f) an object of thought; idea {think the right things} 5 a) [pl.] personal belongings; also, clothes or clothing b) a dress, garment, etc. {not a thing to wear} 6 [pl.] articles, devices, etc. used for some purpose 7 a person: used in expressions of affection, pity, contempt, etc. {poor thing} 8 a being, object, or concept the exact term for which is not known or recalled or is avoided, as from disdain {where did you buy that thing?} 9 [Colloq.] a point of contention; issue {don't make a thing of it} Æ 10 [Colloq.] a complex, often neurotic liking, fear, aversion, etc. with regard to some person, thing, or activity {to have a thing about flying} Æ 11 [Colloq.] what one wants to do or is adept at {do one's own thing} 12 Law that which may be owned; a property: distinguished from PERSON see things [Colloq.] to have hallucinations the thing 1 that which is wise, essential, etc. 2 that which is the height of fashion or style [ME < OE, council, court, controversy, akin to Ger ding, ON thing (orig. sense, public assembly, hence, subject of discussion, matter, thing) < IE *tenk-, to stretch, period of time < base *ten-, to stretch > THIN]

thingamabob or thingumabob (θiŋ´э mэ bäb', -эm э-) •n. [Colloq.] THINGAMAJIG: also thing´um·bob' (-эm bäb') or thing·um·my (θiŋ´gûm'i:, θiŋ´эm i:) [see THINGAMAJIG ]

thingamajig or thingumajig (-jig') •n. [Colloq.] any device, contrivance, gadget, etc.: jocular substitute for a name not known or temporarily forgotten [extension of older thingum, THING]

thing-in-itself (θiŋ´in it self´) •n. NOUMENON [transl. of Ger ding an sich]

-think (thiŋk) combining form forming nouns a pattern or manner of thinking {groupthink}

think piece [Slang] an article, column, etc., as in a newspaper or magazine, presenting news analysis, background material, personal opinion, etc., as distinguished from a straight news account

think tank (or factory) [Slang] a group or center organized, as by a government or business, to do intensive research and problem-solving, esp. with the aid of computers and other sophisticated equipment

think¹ (θiŋk) thought, think´ing •vt. 1 to form or have in the mind; conceive {thinking good thoughts} 2 to hold in one's opinion; judge; consider {many think her charming} 3 to believe; surmise; expect {they think they can come} 4 to determine, resolve, work out, etc. by reasoning {think what your next move should be} 5 [Now Rare] to purpose; intend {thinking to do right} 6 a) to bring to mind; form an idea of {think what the future holds} b) to recall; recollect {think what joy was ours} 7 to have the mind turned steadily toward; have constantly in mind {think success} •vi. 1 to use the mind for arriving at conclusions, making decisions, drawing inferences, etc.; reflect; reason {learn to think} 2 to have an opinion, belief, expectation, etc. {I just think so} 3 to weigh something mentally; reflect {think before you act} 4 to call to mind; recall; remember: with of or about 5 to have an opinion, judgment, etc.: with of or about 6 to allow oneself to consider: with of or about 7 to have regard for; consider the welfare of: with of or about 8 to discover or invent; conceive (of) •n. [Colloq.] the act of thinking {give it a good think} •adj. [Slang] having to do with thinking think (all) the world of to admire or love greatly think better of 1 to form a more favorable opinion of 2 to make a more sensible or practical decision about, after reconsidering think fit to regard as proper or appropriate think little (or nothing) of 1 to attach little (or no) importance, value, etc. to 2 to have little (or no) hesitancy about think nothing of it! you're welcome! think on (or upon) [Archaic] to give thought or consideration to think out 1 to think about completely or to the end 2 to work out, solve, discover, or plan by thinking think out loud to speak one's thoughts as they occur Also think aloud think over to give thought to; ponder well, as for reconsideration think through to think about until one reaches a conclusion or resolution think twice to reconsider; pause to think about again think up to invent, contrive, plan, etc. by thinking think´er •n. SYN.—think is the general word meaning to exercise the mental faculties so as to form ideas, arrive at conclusions, etc. [learn to think clearly]; reason implies a logical sequence of thought, starting with what is known or assumed and advancing to a definite conclusion through the inferences drawn [he reasoned that she would accept]; cogitate is used, sometimes humorously, of a person who is, or appears to be, thinking hard [I was cogitating, not daydreaming]; reflect implies a turning of one's thoughts on or back on a subject and connotes deep or quiet continued thought [he reflected on the day's events]; speculate implies a reasoning on the basis of incomplete or uncertain evidence and therefore stresses the conjectural character of the opinions formed [to speculate on the possibility of life on Mars]; deliberate implies careful and thorough consideration of a matter in order to arrive at a conclusion [the jury deliberated on the case] [< ME thenchen, to think, confused with thinchen, to seem < OE thencan < PGmc *thankjan, to think: for IE base see THANK]

think² (θiŋk) thought v.impersonal to seem: obs., except in archaic METHINKS, METHOUGHT [< ME thinchen, to seem, confused with thenchen, to think: see THINK1]

thinkable (θiŋk´э bэl) •adj. 1 that can be thought; conceivable 2 that can be considered as a possibility

thinking (θiŋk´iŋ) •adj. 1 that thinks or can think; rational 2 given to thought; reflective •n. the action of one who thinks or the result of such action; thought put on one's thinking cap to begin careful thinking about a problem

thinner (θin´эr) •n. a person or thing that thins; esp., a substance added, as turpentine to paint, for thinning

thinnish (θin´ish) •adj. somewhat thin

thin-skinned (θin´skind') •adj. 1 having a thin skin 2 easily hurt by criticism, insult, etc.; sensitive

thio- (θai´ou, -э) combining form sulfur: used in many chemical terms to indicate the replacement of oxygen by divalent sulfur {thiourea} [< Gr theion, brimstone, sulfur, ult. < IE *dhwes- < base *dheu-, to smoke, fume > DULL]

thio acid (θai´ou) an acid in which part or all of the oxygen atoms in the molecule have been replaced by sulfur atoms [see THIO-]

thioacetic acid (θai'ou э si:t´ik, -set´-) a yellowish liquid, CH3COSH, with a very pungent odor: used as a chemical reagent and tear gas [prec. + ACETIC]

thioaldehyde (θai'ou æl´dэ haid') •n. any of a group of organic chemical compounds containing the group or the monovalent radical CHS; an aldehyde in which sulfur has replaced the oxygen [THIO- + ALDEHYDE]

thioantimonate (-æn´tэ mэ neit') •n. any of a group of chemical compounds considered salts of thioantimonic acid Also thi'o·an'ti·mo´ni·ate' (-mou´ni: eit')

thioantimonic acid (-æn'tэ män´ik, -mou´nik) a hypothetical acid, H3SbS4, known only in the form of its salts [THIO- + ANTIMONIC]

thioantimonious acid (-æn'tэ mou´ni: эs) any of a group of hypothetical acids, H3SbS3, HSbS2, and H4Sb2S5, known only in the forms of their salts in solution [THIO- + ANTIMONIOUS]

thioantimonite (-æn´tэ mэ nait') •n. any of a group of chemical compounds considered salts of the thioantimonious acids

thioarsenate (-är´sэ neit', -nit) •n. any of a group of chemical compounds considered salts of the thioarsenic acids

thioarsenic acid (-är sen´ik) any of three hypothetical acids, H3AsS4, HAsS3, and H4As2S7, known only in the forms of their salts [THIO- + ARSENIC]

thioarsenious acid (-är si:´ni: эs) any of a group of hypothetical acids, H3AsS3, HAsS2, and H4As2S5, known only in the forms of their salts [THIO- + ARSENIOUS]

thioarsenite (-är´sэ nait') •n. any of a group of chemical compounds considered salts of the thioarsenious acids

thiobacteria (-bæk tir´i: э) sing. -ri·um (-эm) •n.pl. bacteria found esp. in stagnant water and at the bottom of the sea, that oxidize or reduce sulfur compounds, as hydrogen sulfide [THIO- + BACTERIA]

thiocarbamide (-kär´bэ maid') •n. THIOUREA

thiocyanate (-sai´э neit') •n. 1 a salt of thiocyanic acid containing the monovalent, negative radical SCN 2 an uncharged ester of this acid

thiocyanic acid (-sai æn´ik) a colorless, unstable liquid, HSCN, with a penetrating odor, known chiefly in the form of its salts [THIO- + CYANIC]

Thiokol (θai´э köl', -koul') trademark for any of various synthetic rubbery materials prepared by reacting aliphatic compounds containing two halogen atoms with an alkali polysulfide: they are resistant to oil, grease, and water and are used as sealants, for hosing and tank linings, etc. [arbitrary coinage]

thiol (θai´öl', -oul') •n. any of various organic compounds derived from hydrogen sulfide, esp. a mercaptan [THI(O)- + -OL¹]

thionate (θai´э neit') •n. a salt or ester of a thionic acid

thionic (θai än´ik) •adj. of, containing, or derived from sulfur [< Gr theion, sulfur (see THIO-) + -IC]

thionic acid 1 any organic chemical compound containing the monovalent radical CS·OH 2 any of a group of acids with the general formula H2SnO6, in which n varies from 2 to 6

thionine (θai´э ni:n', -nin) •n. a dark-green crystalline thiazine base, C12H9N3S, producing a violet dye in solution, used esp. as a stain in microscopy [< Gr theion, sulfur (see THIO-) + -INE³]

thionyl (θai´э nil) •n. any of a group of inorganic compounds containing the divalent radical SO: see SULFOXIDE [< Gr theion, sulfur (see THIO-) + -YL]

thiopental sodium (θai'ou pen´tæl', -töl') a yellowish-white, hygroscopic powder, C11H17N2O2SNa, injected intravenously in solution as a general anesthetic and hypnotic [THIO- + PENT(A)- + -AL]

thiophene (θai´э fi:n') •n. a heterocyclic, colorless liquid, C4H4S, resembling benzene and found in coal tar [THIO- + obs. phene, benzene < Fr phène: see PHEN-]

thiophosphate (θai'ou fäs´feit') •n. a salt or ester of a thiophosphoric acid

thiophosphoric acid (-fäs för´ik) 1 a phosphoric acid in which one or more oxygen atoms have been replaced by a sulfur atom 2 the unstable acid, H3PO3S, produced only in solution or as a salt

thiosinamine (-sin æm´i:n, -sin´э mi:n') •n. a colorless, crystalline chemical compound, C4H8N2S, produced by the reaction of ammonia on mustard oil, used in medicine for resolving scar tissue and in industry as a reagent [THIO- + sinamine (< L sinapis, mustard + AMINE)]

thiosulfate (-sûl´feit') •n. a salt or ester of thiosulfuric acid; esp., sodium thiosulfate

thiouracil (-yur´э sil) •n. a white, crystalline, bitter-tasting powder, C4H4N2OS, used to reduce thyroid activity, and in treating angina pectoris [THIO- + URACIL]

thiourea (-yu: ri:´э, -yur´i: э) •n. a colorless, crystalline chemical compound, CS(NH2)2, used in organic synthesis, in photography, etc. [ModL: see THIO- & UREA]

thiram (θai´ræm') •n. a yellow or white powder, C6H12N2S4, used as a rubber accelerator and vulcanizer, fungicide, seed disinfectant, etc. [< ? thiuram < prec. + AM(YL)]

third (θørd) •adj. 1 preceded by two others in a series; 3d or 3rd 2 next below the second in rank, power, value, merit, excellence, etc. 3 designating any of the three equal parts of something •adv. in the third place, rank, group, etc. •n. 1 the one following the second 2 any person, thing, class, place, etc. that is third 3 any of the three equal parts of something; ¹/3 4 the third forward gear of a transmission: it provides more speed but less torque than second 5 Music a) the third tone of an ascending diatonic scale, or a tone two degrees above or below any given tone in such a scale; mediant b) the interval between two such tones, or a combination of them [ME thirde, altered by metathesis < thridde < OE thridda < IE *trtiyo- (< base *trei-, THREE) > L tertius, Gr tritos]

third base Baseball 1 the base between second base and home plate, located on the pitcher's right 2 the position of the infielder at or near this base

third degree 1 in Freemasonry, the degree of master mason Æ 2 [Colloq.] harsh, grueling treatment and questioning of a prisoner in order to force a confession or exact information: often preceded by the [orig. ? fig. use of ritual by Freemasons] third´-de·gree´ •adj.

third dimension 1 a) the dimension of depth in something as distinguished from the two dimensions of any of its flat surfaces b) the quality of having, or of seeming to have, such depth, or solidity 2 the quality of being true to life or seeming real third´-di·men´sion·al •adj.

third estate see ESTATE (sense 2)

third eyelid NICTITATING MEMBRANE

third force [occas. T- F-] a third element, group, bloc, etc. functioning as a counterbalancing, neutralizing, or moderating force or influence in a struggle between two established powers; specif., a coalition of nations for this purpose internationally

Third International COMINTERN

third market over-the-counter trading of listed stocks

Third Order [occas. t- o-] an association of persons (tertiaries) affiliated with a religious order

third party Æ 1 a political party organized to compete against the two major parties in a two-party system 2 a person in a case or matter other than the principals

third person 1 Gram. a) the form of a pronoun (as she) or verb (as is) that refers to the person(s) or thing(s) spoken of in a given utterance b) a category consisting of such forms 2 narration characterized by the general use of such forms

third rail an extra rail used in some electric railways, instead of an overhead wire, for supplying power

Third Reich see REICH

Third Republic the republic established in France in 1870, after the fall of Napoleon III, lasting until the German occupation of France in World War II

third stream a kind of music that combines techniques of jazz improvisation with the forms and instrumentation of classical music third´-stream´ •adj.

third ventricle one of the four cavities of the brain, lying on the midline between the cerebral hemispheres

third world [often T- W-] the underdeveloped or emergent countries of the world

third-class (θørd´klæs´) •adj. 1 of the class, rank, excellence, etc. next below the second 2 designating or of accommodations next below the second class Æ 3 designating or of a lower-cost class of mail limited to merchandise weighing less than 16 oz. or bulk mailing of identical circulars, bulletins, advertisements, etc. •adv. 1 with accommodations next below the second class {to travel third-class} Æ 2 as or by third-class mail

thirdly (θørd´li:) •adv. in the third place; third: used chiefly in enumerating topics

third-rate (-reit´) •adj. 1 third in quality or other rating; third-class 2 inferior; very poor third´-rat´er •n.

thirl (θørl) •vt., vi. [Brit. Dial.] 1 to pierce; perforate 2 var. of THRILL [ME thirlen < OE thyrlian, to bore < thyrel, hole < thurh, THROUGH]

thirst (θørst) •n. 1 the uncomfortable or distressful feeling caused by a desire or need for water and characterized generally by a sensation of dryness in the mouth and throat 2 [Colloq.] a craving for a specific liquid, esp. for alcoholic liquor 3 any strong desire; craving {a thirst for fame} •vi. 1 to be thirsty 2 to have a strong desire or craving [ME < OE thurst, akin to Ger durst < IE base *ters-, to dry > L torrere, to parch, torridus, torrid, terra, earth]

thirsty (θørs´ti:) thirst´i·er, thirst´i·est •adj. 1 feeling thirst; wanting to drink 2 a) lacking water or moisture; dry; parched {thirsty fields} b) very absorbent 3 [Colloq.] causing thirst {thirsty work} 4 having a strong desire; craving thirst´i·ly •adv. thirst´i·ness •n. [ME thyrsti < OE thurstig]

thirteen (θør´ti:n´) •adj. three more than ten •n. the cardinal number between twelve and fourteen; 13; XIII [ME thrittene < OE threotyne: see THREE & -TEEN]

thirteenth (θør´ti:nθ´) •adj. 1 preceded by twelve others in a series; 13th 2 designating any of the thirteen equal parts of something •n. 1 the one following the twelfth 2 any of the thirteen equal parts of something; ¹/13 •adv. in the thirteenth place, rank, group, etc. [ME thirtenth: see THIRTEEN & -TH²]

thirtieth (θørt´i: iθ) •adj. 1 preceded by twenty-nine others in a series; 30th 2 designating any of the thirty equal parts of something •n. 1 the one following the twenty-ninth 2 any of the thirty equal parts of something; ¹/30 •adv. in the thirtieth place, rank, group, etc. [< ME thrittythe < OE thritigotha: see THIRTY & -TH²]

thirty (θørt´i:) •adj. three times ten •n. pl. -ties 1 the cardinal number between twenty-nine and thirty-one; 30; XXX Æ 2 this number used to signify the end of a dispatch, story, etc., as for a newspaper [prob. orig. telegraphers' code for a concluding sentence] the thirties the numbers or years, as of a century, from thirty through thirty-nine [LME thirti, metathetic for thritti < OE thritig < thri, THREE + -tig, -TY²]

Thirty Years' War a series of European wars (1618-48) on political and religious issues, fought orig. between German Catholics and German Protestants, but later involving the Swedish, French, and Spanish

thirty-second note (θørt'i: sek´эnd) Music a note having one thirty-second the duration of a whole note: see NOTE, illus.

thirty-twomo (-tu:´mou') pl. -mos' •n. 1 the page size of a book made up of printer's sheets folded into 32 leaves, each leaf being approximately 3½ by 5½ in. 2 a book consisting of pages of this size Usually written 32mo or 32° •adj. consisting of pages of this size [see -MO]

this (ðis) pl. these pron. 1 the person or thing mentioned or understood {this is John, this tastes good} 2 the thing that is nearer than another referred to as that {this is larger than that} 3 the less remote in thought of two contrasted things {of the two possibilities, this is more likely than that} 4 the fact, idea, etc. that is being, or is about to be, mentioned, presented, etc. {this convinces us; now hear this} •adj. pl. these 1 designating the person or thing mentioned or understood {this man was John; this pie tastes good} 2 designating the thing that is nearer than the one referred to as that {this desk is smaller than that one} 3 designating the less remote in thought of two contrasted things {of the two, this possibility is more likely than that} 4 designating something that is being, or is about to be, mentioned, presented, etc. {hear this song; this fact will convince you} 5 [Colloq.] designating a particular but unspecified person or thing {there's this lady in Iowa} •adv. to this extent; so {it was this big} [ME this, thes < OE thes, masc., this, neut. < base of the demonstrative pron.: see THAT]

Thisbe see PYRAMUS AND THISBE

thistle (θis´эl) •n. any of various plants (as genera Onopordum, Cirsium, and Cnicus) of the composite family, with prickly leaves and heads of white, purple, pink, or yellow flowers; esp., the Scotch thistle (O. acanthium) with white down and lavender flowers [ME thistel < OE, akin to Ger distel < IE base *(s)teig-, a point > STICK, Sans tiktá, sharp]

thistledown (θis´эl daun') •n. the down attached to the flower head of a thistle

thistly (θis´li:, -эl i:) -tli·er, -tli·est •adj. 1 like a thistle or thistles; prickly 2 full of thistles

thither (ðið´эr, θið´-) •adv. to or toward that place; there •adj. on or toward that side; farther [ME thider < OE < demonstrative base: see THAT]

thitherto (ðið´эr tu:', θið´-; θið'эr tu:´, ðið'-) •adv. until that time; till then [ME thidir to]

thitherward (-wэrd) •adv. [Now Rare] toward that place; thither: also thith´er·wards [ME < OE thiderweard]

thixotropy (θiks ä´trэ pi:) •n. the property of certain gels and emulsions of becoming fluid when agitated and then setting again when left at rest thix'o·trop´ic (-ou träp´ik, -э träp´-) •adj. [< Gr thixis, touching (< thinganein, to touch: see THIGMOTAXIS) + -O- + -TROPY]

ThM or Th.M. Master of Theology [L Theologiae Magister]

tho or tho' (ðou) conj., adv. short for THOUGH

thole¹ (θoul) •n. a pin or either of a pair of pins made of metal or wood and set vertically in the gunwale of a boat to serve as a fulcrum for an oar: also thole´pin' (-pin') [ME tholle < OE thol, akin to ON thollr, Du dol < IE *teul- < base *tēu-, to swell > THUMB]

thole² (θoul) tholed, thol´ing •vt. [Now Dial., Chiefly Brit.] to suffer; endure; undergo [ME tholen < OE tholian < IE base *tel-, to bear > TOLERATE]

Thomas (täm´эs) 1 a masculine name: dim. Tom, Tommy; fem. Thomasina 2 Bible (called Didymus, the Twin) one of the twelve Apostles, who doubted at first the resurrection of Jesus: John 20:24-29: his day is Dec. 21: also Saint Thomas 3 Clarence 1948- ; associate justice, U.S. Supreme Court (1991- ) 4 Dyl·an (Marlais) (dil´эn) 1914-53; Welsh poet 5 George Henry 1816-70; Union general in the Civil War 6 Norman (Mattoon) 1884-1968; U.S. Socialist leader 7 (Philip) Edward 1878-1917; Eng. poet 8 Seth 1785-1859; U.S. clock manufacturer [ME < LL(Ec) < Gr(Ec) Thōmas < Heb teom, Aram teoma, lit., a twin]

Thomas à Becket see BECKET, Saint Thomas à

Thomas à Kempis see KEMPIS, Thomas à

Thomas Aquinas see AQUINAS, Saint Thomas

Thomism (tou´miz'эm) •n. the theological and philosophical doctrines of Thomas Aquinas and his followers, which formed the basis of 13th-cent. scholasticism Tho´mist •adj., n. Tho·mis´tic •adj.

Thompson (tämp´sэn, täm-) 1 Benjamin Count Rumford 1753-1814; Brit. scientist & statesman, born in America 2 David 1770-1857; Cdn. explorer, born in England 3 Francis 1859-1907; Eng. poet

Thompson submachine gun a type of submachine gun: see SUBMACHINE GUN [after a co-inventor, J. T. Thompson (1860-1940), U.S. army officer]

Thomson (täm´sэn, tämp´-) 1 Sir George Pag·et (pæj´it) 1892-1975; Eng. physicist 2 James 1700-48; Scot. poet 3 James (pseud. B.V.; i.e., Bysshe Vanolis) 1834-82; Scot. poet 4 Sir J(ohn) Arthur 1861-1933; Scot. naturalist & writer 5 Sir Joseph John 1856-1940; Eng. physicist: father of Sir George 6 Virgil 1896-1989; U.S. composer 7 William see KELVIN, 1st Baron

-thon (θän) suffix -ATHON: used after a vowel {radiothon}

Thonburi (tûn bur´i:, tän-; tän'bu: ri:´) city in Thailand, on the Chao Phraya River, opposite Bangkok: pop. 628,000

thong (θöŋ) •n. 1 a narrow strip of leather, etc. used as a lace, strap, etc. 2 a whiplash, as of plaited strips of hide 3 a kind of sandal consisting usually of a flat rubber sole held on the foot by a strap slipped between the big toe and the toe next to it [ME < OE thwang, twisted string, thong: see TWINGE]

Thonga (täŋ´gэ) •n. 1 pl. -gas or -ga a member of a people of Mozambique 2 the Bantu language of this people

Thor (θör) Norse Myth. the god of thunder, war, and strength, and the son of Odin, armed with a magic hammer [ON Thorr: see THUNDER]

thoracic (θou ræs´ik, θö-, θэ-) •adj. of, in, or near the thorax [ModL thoracicus < Gr thōrakikos]

thoracic duct the main canal of the lymphatic system, passing along the front of the spinal column, collecting lymph and conveying it into the left subclavian vein

thoraco- (θör´э kou', θou´rэ-) combining form 1 thorax {thoracotomy} 2 thorax and {thoracolumbar} Also, before a vowel, thorac- [Gr thōrako-]

thoracolumbar (θör'э kou lûm´bэr, θö'rэ-) •adj. 1 of the thoracic and lumbar regions 2 SYMPATHETIC (sense 4)

thoracotomy (θör'э kät´э mi:, θou'rэ-) pl. -mies •n. surgical incision into the thorax [THORACO- + -TOMY]

thorax (θör´æks') pl. -rax'es or -ra·ces' (-э si:z') •n. 1 in tetrapods, including humans, a) the part of the body cavity from the neck or head to the abdomen, containing the heart, lungs, etc.; chest: in mammals, the diaphragm separates it from the abdomen b) the area of the trunk covering this part 2 in arthropods, the body segment between the head and abdomen to which the legs are attached: see CEPHALOTHORAX, INSECT, illus. [ME < L < Gr thōrax, chest, breastplate]

Thorazine (θör´э zi:n') •n. CHLORPROMAZINE [thor- (< ?) + (CHLORPROM)AZINE]

Thoreau (thör´ou; θö rou´, θэ-), Henry David (born David Henry Thoreau) 1817-62; U.S. naturalist & writer

thoria (θör´i: э) •n. thorium oxide, ThO2, a white, earthy powder: used esp. in gas mantles and in making refractory crucibles [ModL < Swed Thorjord, lit., Thor-earth (so named by BERZELIUS): see THORIUM]

thorianite (-nait') •n. a black, crystalline, radioactive mineral, consisting usually of 70% thorium oxide, 12% uranium oxide, and various rare earths [< prec. + -ITE¹]

thorite (θör´ait') •n. a dark-brown or black mineral, ThSiO4, a native silicate of thorium [Swed thorit: see THORIUM & -ITE¹]

thorium (θör´i: эm, θou´ri:-) •n. a rare, grayish, radioactive chemical element occurring in monazite and thorite: it is used in magnesium alloys, the making of gas mantles, electronic equipment, etc., and as a nuclear fuel: symbol, Th; at. wt., 232.038; at. no., 90; sp. gr., 11.7; melt. pt., 1,750°C; boil. pt., c. 4,800°C tho´ric •adj. [ModL: so named (1829) by BERZELIUS, its discoverer < ON Thorr (see THOR) + -IUM]

thorn (θörn) •n. 1 a) a very short, hard, leafless branch or stem with a sharp point b) any small tree or shrub bearing thorns, as a hawthorn c) the wood of any of these trees d) PRICKLE 2 a sharp, pointed protuberance on an animal; spine 3 anything that keeps troubling, vexing, or irritating one, like a constantly pricking thorn: usually in the phrase thorn in one's side (or flesh) 4 name of a rune in the Old English and Old Norse alphabets (þ), used to represent the voiced or voiceless interdental fricative: in Middle English orthography it was gradually replaced by th [ME < OE, akin to Ger dorn < IE *(s)ter-, prickly plant (< base *ster-, to be stiff) > Gr ternax, cactus stem]

thorn apple 1 HAWTHORN 2 its applelike fruit Æ 3 a jimson weed or similar plant

thornback (θörn´bæk') •n. 1 any of several European rays with many tubercles on the back and a double row of spines on the tail 2 a large European spider crab (Maja squinado) with a spiny back 3 a guitarfish (Platyrhinoidis triseriata) with spines on the back, found in the Pacific

Thorndike (θörn´daik'), Edward Lee 1874-1949; U.S. psychologist, educator, & lexicographer

Thornton (θörn´tэn, θörnt´ªn) city in NE Colo., north of Denver: pop. 55,000 [after Dan Thornton, governor of Colo. (1956)]

thorny (θörn´i:) thorn´i·er, thorn´i·est •adj. 1 full of thorns; brambly; prickly 2 having thorns or spines: said of some animals 3 like a thorn; sharp 4 full of obstacles, vexations, pain, etc. {the thorny road to peace} 5 full of controversial points; difficult; contentious {a thorny problem} thorn´i·ness •n.

thoro (θør´ou) •adj. short for THOROUGH

thoron (θör´än) •n. a radioactive isotope of radon, resulting from the disintegration of thorium [ModL < THOR(IUM) + -on as in ARGON]

thorough (θør´ou; Brit θû´rэ) •prep., adv. obs. var. of THROUGH •adj. 1 orig., passing through: now chiefly in combination, as in thoroughfare 2 done or proceeding through to the end; omitting nothing; complete {a thorough checkup} 3 that is completely (the thing specified); out-and-out; absolute {a thorough rascal} 4 very exact, accurate, or painstaking, esp. with regard to details {a thorough researcher} •n. [T-] Eng. History the ruthlessly thoroughgoing administrative policies carried out by William Laud and the Earl of Strafford during the reign of Charles I thor´ough·ly (-ou li:, -э li:) •adv. thor´ough·ness •n. [ME thoruh, thuruh, an emphatic var. of through, THROUGH]

thorough bass Music 1 a) an old system for indicating accompanying chords by putting figures under the bass notes b) the figures used 2 loosely, the theory of harmony

thorough brace either of a pair of leather straps supporting the body of a coach or other horse-drawn vehicle and often serving as springs

thoroughbred (θør´ou bred', θør´э-) •adj. 1 purebred, as a horse or dog; pedigreed 2 thoroughly trained, educated, cultured, etc.; well-bred 3 excellent; first-rate •n. 1 [T-] any of a breed of light horse developed by crossing Arabian and Turkish stallions with English mares: it is bred primarily for racing 2 a cultured, well-bred person

thoroughfare (-fer') •n. 1 a way or passage through 2 a public street open at both ends, esp. one through which there is much traffic; highway; main road [ME thurghfare: see THROUGH & FARE]

thoroughgoing (-gou´iŋ) •adj. very thorough; specif., a) precise and painstaking b) being wholly such; unmitigated

thoroughpaced (-peist') •adj. 1 thoroughly trained in all paces or gaits: said of horses 2 THOROUGHGOING

thoroughpin (-pin') •n. a swelling in the sheath of a tendon in a horse's hock that shows on both sides of the leg

thoroughwort (-wørt') •n. BONESET

thorp or thorpe (θörp) •n. a village; hamlet: now mainly in place names [ME < OE, akin to Ger dorf, village < IE base *treb-, beamed structure, dwelling > MIr treb, house]

Thorpe (θörp), Jim (born James Francis Thorpe) 1888-1953; U.S. athlete

Thos Thomas

those (ðouz) •adj., pron. pl. of THAT [ME thas, thos < OE thas, thæs, pl. of thes, THIS]

Thoth (θouθ; tout) Egypt. Myth. the god of wisdom, learning, and magic, the scribe of the gods: represented as having a human body and the head of either a dog or an ibis [L < Gr Thōth < Egypt dhwty]

thou¹ (ðau) pron. nom. & obj. you or ye; pl. poss. your or yours the nominative second person singular of the personal pronoun Formerly used in familiar address, but now replaced by you except in poetic or religious use and in some British dialects: thee is the objective case form, thy or thine the possessive, and thyself the intensive and reflexive [ME < OE thu, akin to Ger du < IE *tu > L & Sans tu]

thou² (θau) pl. thou •n.or thous [Slang] short for THOUSAND

though (ðou) conj. 1 in spite of the fact that; notwithstanding that; although {though the car is new, it rattles} 2 and yet; nevertheless; however {they will probably win, though no one thinks so} 3 even if; supposing that {though he may fail, he will have tried} •adv. however; nevertheless {she sings well, though} [ME thah, thogh < OE theah & ON tho, akin to Ger doch, yet, however, Goth thauh]

thought¹ (θöt) •n. 1 the act or process of thinking; reflection; meditation; cogitation 2 the power of reasoning, or of conceiving ideas; capacity for thinking; intellect; imagination 3 a result of thinking; idea, concept, opinion, etc. 4 the ideas, principles, opinions, etc. prevalent at a given time or place or among a given people {modern thought in education} 5 attention; consideration; heed {give it a moment's thought} 6 mental engrossment; preoccupation; concentration {deep in thought} 7 intention or expectation {no thought of leaving} 8 a small amount, degree, etc.; a little; trifle {be a thought more careful} SYN. IDEA [ME thouht < OE thoht < PGmc *thanht, pret. of *thankjan (> OE thencan: see THINK¹)]

thought² (θöt) •vt., vi. pt. & pp. of THINK¹ & THINK²

thoughtful (θöt´fэl) •adj. 1 full of thought; meditative; thinking 2 showing or characterized by thought; serious {a thoughtful essay} 3 heedful, careful, attentive, etc.; esp., considerate of others; kind thought´ful·ly •adv. thought´ful·ness •n. SYN.—thoughtful, as compared here, implies the showing of thought for the comfort or well-being of others, as by anticipating their needs or wishes [it was thoughtful of you to call]; considerate implies a thoughtful or sympathetic regard for the feelings or circumstances of others, as in sparing them pain, distress, or discomfort [considerate enough to extend the time for payment]; attentive implies a constant thoughtfulness as shown by repeated acts of consideration, courtesy, or devotion [an attentive suitor] —ANT. thoughtless

thoughtless (θöt´lis) •adj. 1 not stopping to think; careless 2 not given thought; ill-considered; rash 3 not considerate of others; inconsiderate 4 [Rare] stupid; senseless thought´less·ly •adv. thought´less·ness •n.

thousand (θau´zэnd) •n. 1 ten hundred; 1,000; M 2 an indefinite but very large number: a hyperbolic use •adj. amounting to one thousand in number [ME thusend < OE, akin to Ger tausend < PGmc *thus-hundi, many hundred < IE base *tēu-, to swell, increase + PGmc *hund-, HUNDRED]

Thousand Island dressing a salad dressing made of mayonnaise with chili sauce or ketchup and minced pickles, capers, olives, etc.

Thousand Islands group of over 1,500 islands in the St. Lawrence River at the outlet of Lake Ontario, some part of N.Y. State & some of Ontario, Canada

Thousand Oaks city in SW Calif., northwest of Los Angeles: pop. 104,000 [after the many oak trees there]

thousandfold (-fould') •adj. having a thousand times as much or as many •adv. a thousand times as much or as many With a •n. a number or an amount a thousand times as great [prec. + -FOLD]

thousandth (θau´zэndθ; -zэntθ, -zэnθ) •adj. 1 coming last in a series of a thousand; 1,000th 2 designating any of the thousand equal parts of something •n. 1 the thousandth one of a series 2 any of the thousand equal parts of something; ¹/1000 [THOUSAND + -TH²]

Thrace (θreis) 1 ancient region in the E Balkan Peninsula 2 modern region in the SE Balkan Peninsula divided between Greece & Turkey

Thracian (θrei´shэn) •adj. of Thrace, its people, etc. •n. 1 a native or inhabitant of Thrace 2 the extinct language of ancient Thrace, generally assumed to belong to the Indo-European language family

thrall (θröl) •n. 1 orig., a slave or bondman 2 a person under the moral or psychological domination of someone or something 3 slavery •vt. [Archaic] to enslave •adj. [Archaic] enslaved [ME thral < OE thræl < ON thræll < Gmc *thranhilaz, lit., the constrained one < IE base *trenk-, to shove, press hard > THRONG]

thralldom or thraldom (θröl´dэm) •n. the condition of being a thrall; servitude; slavery

thrash (θræsh) •vt. 1 THRESH 2 to make move violently or wildly; beat {a bird thrashing its wings} 3 to give a severe beating to; flog 4 to defeat overwhelmingly •vi. 1 THRESH 2 to move or toss about violently, flinging the arms, legs, etc. about wildly or vigorously {thrashing in agony} 3 to make one's way by thrashing •n. the act of thrashing SYN. BEAT thrash out to settle by detailed discussion thrash over to go over (a problem, etc.) in great detail [ME threschen < OE therscan, akin to Ger dreschen, to thresh < IE base *ter-, to rub > THROW]

thrasher¹ (-эr) •n. a person or thing that thrashes

thrasher² (-эr) •n. Æ any of a group of gray to brownish American passerine birds (family Mimidae) with a long, stiff tail and a long bill, esp. the brown thrasher (Toxostoma rufum) of the E U.S. [E dial. thresher, prob. akin to THRUSH¹]

thrashing (-iŋ) •n. a beating; flogging

thrasonical (θrэ sän´i kэl) •adj. boastful; bragging thra·son´i·cal·ly •adv. [< L Thraso, name of the braggart in Terence's Eunuch (< Gr Thrasōn < thrasos, tharsos, bold < IE base *dhers-, to dare, be bold > DARE) + -ICAL]

thrawn (θrön, θrän) •adj. 1 crooked; twisted 2 perverse [< thraw, dial. form of THROW]

thread (θred) •n. 1 a) a light, fine, stringlike length of material made up of two or more fibers or strands of spun cotton, flax, silk, etc. twisted together and used in sewing b) a similar fine length of synthetic material, as nylon or plastic, or of glass or metal c) the fine, stringy filament extruded by a spider, silkworm, etc. d) any of the yarns of which a fabric is woven e) a fine, stringy length of syrup or other viscous material 2 any thin line, stratum, vein, stream, ray, etc. 3 an element suggestive of a thread in being continuous or sequential {the thread of a story} 4 the helical ridge of a screw, bolt, nut, etc. Æ 5 [pl.] [Slang] a suit, or clothes generally •vt. 1 a) to put a thread through the eye of (a needle, etc.) b) to arrange thread for use on (a sewing machine) 2 to string (beads, etc.) on or as if on a thread 3 to fashion a THREAD (sense 4) on or in (a screw, pipe, etc.) 4 to interweave with or as if with threads {a red tapestry threaded with gold} 5 a) to pass through by twisting, turning, or weaving in and out {to thread the streets} b) to make (one's way) in this fashion 6 to pass or feed (tape, film, etc.) into or through (a recorder, projector, etc.) •vi. 1 to go along or proceed in a winding way Æ 2 to form a thread when dropped from a spoon: said of boiling syrup that has reached a certain consistency thread´er •n. thread´like' •adj. [ME threde < OE thræd (akin to Ger draht) < base of thrawan, to twist: see THROW]

threadbare (-ber') •adj. 1 worn down so that the threads show; having the nap or surface fibers worn off {threadbare rugs} 2 wearing old, worn clothes; shabby 3 that has lost freshness or novelty; stale {a threadbare argument}

threadfin (-fin') •n. any of a family (Polynemidae) of marine percoid fishes having a divided pectoral fin that ends in threadlike rays

threadworm (-wørm') •n. a nematode or gordian worm

thready (θred´i:) thread´i·er, thread´i·est •adj. 1 of or like a thread; stringy; fibrous; filamentous 2 forming threads; viscid: said of liquids 3 of or covered with threads or threadlike parts; fibrous 4 thin, weak, feeble, etc. {a thready voice, a thready pulse} thread´i·ness •n.

threap (θri:p) •vt. [Scot. or North Eng.] 1 to scold; chide 2 to maintain or assert obstinately [ME threpen < OE threapian, to rebuke]

threat (θret) •n. 1 an expression of intention to hurt, destroy, punish, etc., as in retaliation or intimidation 2 a) an indication of imminent danger, harm, evil, etc. {the threat of war} b) a potential source of this •vt., vi. obs. var. of THREATEN [ME threte < OE threat, a throng, painful pressure, akin to Ger (ver)driessen, to grieve, annoy < IE *treud-, to push, press (prob. < base *ter-, to rub) > L trudere, to THRUST]

threaten (θret´ªn) •vt. 1 a) to make threats against; express one's intention of hurting, punishing, etc. b) to express intention to inflict (punishment, reprisal, etc.) 2 a) to be a menacing indication of (danger, harm, distress, etc.) {clouds threatening snow} b) to be a source of such danger, harm, etc. to {an epidemic that threatens the city} •vi. 1 to make threats 2 to be an indication or source of potential danger, harm, etc. threat´en·er •n. threat´en·ing·ly •adv. SYN.—threaten implies a warning of impending punishment, danger, evil, etc. by words, actions, events, conditions, signs, etc. [he threatened to retaliate, the clouds threaten rain]; menace stresses the frightening or hostile character of that which threatens [he menaced me with a revolver] [ME thretnen < OE threatnian]

threatened species a species of animal or plant that is rare and may become an endangered species in the near future

three (θri:) •adj. totaling one more than two •n. 1 the cardinal number between two and four; 3; III 2 any group of three people or things 3 something numbered three or having three units, as a playing card, domino, face of a die, etc. [ME < OE threo, thrie, akin to Ger drei < IE base *trei- > L tres, Gr treis, Sans tri]

three R's reading, writing, and arithmetic, regarded as the basic elementary studies and the fundamentals of an education: so called from the humorous spelling reading, 'riting, and 'rithmetic: with the

three-base hit (θri:´beis´) Baseball a hit on which the batter reaches third base: also [Slang] three´-bag´ger (-bæg´эr) •n.

three-card monte (θri:´kärd´ män´ti:) a gambling game in which a person bets on the location of one of three cards shown and then, placed face down, shifted about

three-color (θri:´kûl'эr) •adj. designating or of a full-color printing process using three separate plates, each reproducing one primary color

three-cornered (-kör´nэrd) •adj. having three corners or angles

three-decker (θri:´dek´эr) •n. 1 a) [Historical] a warship with three decks of cannon b) a ship with three decks 2 any structure with three levels 3 [Colloq.] a sandwich made with three slices of bread

three-dimensional (-dэ men´shэ nэl) •adj. 1 a) of or having three dimensions b) appearing to have depth or thickness in addition to height and width 2 having a convincing or lifelike quality

threefold (-fould') •adj. 1 having three parts 2 having three times as much or as many •adv. three times as much or as many [THREE + -FOLD]

three-four (-för´) •adj. designating or of a musical rhythm with three quarter notes to a measure

three-mile limit (θri:´mail´) the outer limit of a zone of water extending three miles offshore, sometimes regarded as the extent of the territorial jurisdiction of the coastal country

threepence (θrip´эns, θrûp´-, θrep´-) •n. 1 the sum of three British pence 2 a British coin of this value

threepenny (θri:´pen'i:, θrip´э ni:) •adj. 1 worth or costing threepence 2 of small worth; cheap 3 designating a size of nail: see -PENNY

three-phase (θri:´feiz´) •adj. Elec. designating or of a combination of three circuits energized by three alternating electromotive forces differing in phase by one third of a cycle, or 120 electrical degrees

three-piece (θri:´pi:s´) •adj. composed of three separate pieces, as an outfit of skirt, sweater, and jacket

three-ply (-plai´) •adj. having three thicknesses, interwoven layers, strands, etc.

three-point landing (θri:´point´) a perfect airplane landing in which the main wheels and the tail wheel or nose wheel touch the ground at the same time

three-point play Basketball a play in which a player is fouled while making a two-point field goal and subsequently scores a one-point free throw

three-quarter (θri:´kwört´эr) •adj. 1 of or involving three fourths 2 showing the face intermediate between profile and full face {a three-quarter portrait}

three-quarter binding a type of bookbinding in which the material of the back, usually leather, is extended onto the covers for one third of their width

three-ring circus (θri:´riŋ´) 1 a circus having three rings for simultaneous performances 2 any situation or event hilariously or confusingly packed with action

threescore (θri:´skör´) •adj., n. three times twenty; sixty

threesome (θri:´sэm) •adj. of or engaged in by three •n. 1 a group of three persons 2 Golf a) a match in which one participant plays against two others, who alternate strokes on a single ball b) a group of three people playing golf against each other, each using his or her own ball [ME thresum: see -SOME²]

three-square (θri:´skwer´) •adj. forming an equilateral triangle in cross section, as a three-cornered file

three-way (θri:´wei´) •adj. operating in three ways; specif., designating or for a light bulb with two filaments that can be switched on singly or together for three different wattages

three-wheeler (-hwi:l´эr, -wi:l´-) •n. a three-wheeled vehicle, as a tricycle or a three-wheeled motorcycle

thremmatology (θrem'э täl´э ji:) •n. [Rare] the branch of biology dealing with the breeding of domestic animals and plants [< Gr thremma (gen. thremmatos), nursling (< IE base *dherebh-, to coagulate > Gr trephein, to nourish, thrombos, a clot) + -LOGY]

threnody (θren´э di:) pl. -dies a song of lamentation; funeral song: also thre·node (θri:´noud, θren´oud) •n. thre·nod·ic (θri: näd´ik) •adj. thren´o·dist •n. [Gr thrēnōidia < thrēnos, lamentation (< IE echoic base *dhren-, to murmur > DRONE¹) + ōidē, song]

threonine (θri:´э ni:n', -nin) •n. an essential amino acid, CH3CH(OH)CH(NH2)COOH, obtained from the hydrolysis of many proteins [prob. < threon(ic acid) + -INE³]

thresh (θresh) •vt. 1 to beat out (grain) from its husk, as with a flail 2 to beat grain out of (husks) 3 to beat or strike as with a flail •vi. 1 to thresh again 2 to toss about; thrash thresh out THRASH OUT (see phrase under THRASH) [ME threschen: earlier form of THRASH]

thresher (θresh´эr) •n. 1 a person who threshes 2 THRESHING MACHINE 3 any of a family (Alopiidae, order Lamniformes) of large sharks of temperate and tropical seas, having a very long upper tail lobe, which supposedly threshes the water and drives its prey together

threshing machine a machine for threshing grain

threshold (θresh´ould', -hould') •n. 1 DOORSILL 2 the entrance or beginning point of something {at the threshold of a new career} 3 Physiol., Psychol. the point at which a stimulus is just strong enough to be perceived or produce a response {the threshold of pain} [ME threschwold < OE therscwold (akin to ON threskolder) < base of therscan (see THRASH) + ?]

threw (θru:) •vt. pt. of THROW

thrice (θrais) •adv. 1 three times 2 three times as much or as many; threefold; triply 3 greatly; highly [ME thries < thrie (< OE thriwa, thrice, akin to threo, THREE) + -(e)s, adv. gen. suffix, after ones (see ONCE)]

thrift (θrift) •n. 1 orig., a) the condition of thriving; prosperity b) physical thriving; vigorous growth 2 careful management of one's money or resources; economy; frugality 3 any of a genus (Armeria, family Plumbaginaceae) of dwarf, evergreen, perennial dicotyledonous plants (order Plumbaginales) with narrow leaves and small, white, pink, red, or purplish flowers Æ 4 a mutual savings bank, savings and loan association, or credit union: usually used in pl.: in full thrift institution 5 [Brit. Dial.] a means of thriving; work; labor [ME < ON < thrifast, to prosper: see THRIVE]

thrift shop a store where castoff clothes and rummage are sold, specif. to raise money for charity

thriftless (θrift´lis) •adj. without thrift; wasteful thrift´less·ly •adv. thrift´less·ness •n.

thrifty (θrif´ti:) thrift´i·er, thrift´i·est •adj. 1 practicing or showing thrift; economical; provident 2 thriving; flourishing; prospering 3 growing vigorously, as a plant thrift´i·ly •adv. thrift´i·ness •n. SYN.—thrifty implies industry and clever management of one's money or resources, usually so as to result in some savings [the thrifty housewife watched for sales]; frugal stresses the idea of saving and suggests spending which excludes any luxury or lavishness and provides only the simplest fare, dress, etc. [the Amish are a frugal people]; sparing implies such restraint in spending as restricts itself to the bare minimum or involves deprivation [sparing to the point of niggardliness]; economical implies prudent management of one's money or resources so as to avoid any waste in expenditure or use [it is often economical to buy in large quantities]; provident implies management with the foresight to provide for future needs [never provident, he quickly spent his inheritance] —ANT. lavish, prodigal, wasteful

thrill (θril) •vt. 1 to cause sharply exhilarating excitement in; make shiver or tingle with excitement 2 to produce vibrations or quivering in; cause to tremble •vi. 1 to feel emotional excitement; shiver or tingle with excitement 2 to tremble; vibrate; quiver •n. [new formation < the v.] 1 a thrilling or being thrilled; tremor of excitement 2 the quality of thrilling, or the ability to thrill {the thrill of the chase} 3 something that causes emotional excitement 4 a) a vibration; tremor; quiver b) Med. an abnormal tremor, as of the circulatory system, that can be felt by the hand on palpation [ME thrillen, by metathesis < thyrlen < OE thyr(e)lian, to pierce < thyrel, perforation, hole < base of thurh, THROUGH]

thriller (θril´эr) •n. 1 a person or thing that thrills 2 a) a suspenseful novel, play, film, etc. b) [Chiefly Brit., etc.] such a novel, film, etc. dealing with crime and detection

thrips (θrips) pl. thrips •n. any of an order (Thysanoptera) of very small, destructive, usually winged insects that suck the juices of plants [L < Gr, lit., wood-worm]

thrive (θraiv) thrived or throve, thrived or thriv·en (θriv´ªn), thriv´ing •vi. 1 to prosper or flourish; be successful, esp. as the result of economical management 2 to grow vigorously or luxuriantly; improve physically [ME thrifen < ON thrifast, to prosper, reflex. of thrifa, to grasp]

thro' or thro (θru:) •prep., adv., adj. archaic contr. for THROUGH

throat (θrout) •n. 1 the front part of the neck 2 the upper part of the passage leading from the mouth and nose to the stomach and lungs, including the pharynx and the upper larynx, trachea, and esophagus 3 any narrow passage, part, or entrance •vt. [Archaic] to pronounce or sing in the throat, i.e., with a harsh, guttural quality cut each other's throats [Colloq.] to ruin each other, as by underselling in business cut one's own throat [Colloq.] to be the means of one's own ruin jump down someone's throat [Colloq.] to attack or criticize someone suddenly and violently ram something down someone's throat to force someone to accept, hear, etc. something stick in one's throat to be hard for one to say, as from reluctance [ME throte < OE, akin to Ger dross(el), throat < IE *(s)treu-, swollen, stretched < base *(s)ter-, stiff > STARE]

-throated (θrout´id) combining form having a (specified kind of) throat {ruby-throated hummingbird}

throatlatch (θrout´læch') •n. a strap that passes under a horse's throat, for holding a bridle or halter in place: see HARNESS, illus.

throaty (θrout´i:) throat´i·er, throat´i·est •adj. 1 produced in the throat, as some sounds or tones 2 characterized by such sounds; husky, hoarse, etc. {a throaty voice} throat´i·ly •adv. throat´i·ness •n.

throb (θräb) throbbed, throb´bing •vi. 1 to beat, pulsate, vibrate, etc. 2 to beat strongly or fast; palpitate, as the heart under exertion 3 to feel or express emotion; quiver with excitement •n. 1 the act of throbbing 2 a beat or pulsation, esp. a strong one of the heart throb´ber •n. throb´bing·ly •adv. [ME throbben, prob. of echoic orig.]

throe (θrou) •n. a spasm or pang of pain: usually used in pl. {the throes of childbirth, death throes} in the throes of in the act of struggling with (a problem, decision, task, etc.) [ME throwe, prob. < OE thrawu, pain, affliction, akin to ON thrā, strong yearning < IE *treu- (> Gr trauma, a wound) < base *ter-, to rub, grind > THROW]

thrombin (θräm´bin) •n. the enzyme of the blood, formed from prothrombin, that causes clotting by converting fibrinogen to fibrin [THROMB(US) + -IN¹]

thrombo- (θräm´bou, -bэ) combining form thrombus, blood clot {thrombocyte} [< Gr thrombos, a clot: see THROMBUS]

thrombocyte (θräm´bou sait') •n. 1 a small nucleated blood cell in most vertebrates, except mammals, that initiates the process of blood clotting 2 PLATELET (sense 1) throm'bo·cyt´ic (-sit´ik) •adj. [prec. + -CYTE]

thromboembolism (θräm'bou em´bэ liz'эm) •n. the obstruction of a blood vessel by an embolus that has broken away from a thrombus throm'bo·em·bol´ic (-bäl´ik) •adj. [THROMBO- + EMBOLISM]

thrombogen (θräm´bou jэn, -jen'; -bэ-) •n. PROTHROMBIN [THROMBO- + -GEN]

thrombokinase (θräm'bou kai´neis', -kin´eis') •n. THROMBOPLASTIN [THROMBO- + KINASE]

thrombophlebitis (θräm'bou flэ bait´эs) •n. the formation of a clot in a vein, with associated irritation of the vein's inner lining [THROMBO- + PHLEBITIS]

thromboplastic (-plæs´tik) •adj. 1 of or having the properties of a thromboplastin 2 initiating or hastening the clotting of blood throm'bo·plas´ti·cal·ly •adv.

thromboplastin (-plæs´tin) •n. a substance released from blood platelets and injured body tissues that assists in the clotting of the blood by initiating the conversion of prothrombin to thrombin [THROMBO- + -PLAST + -IN¹]

thrombosis (θräm bou´sis) •n. coagulation of the blood in the heart or a blood vessel, forming a clot throm·bot´ic (-bät´ik) •adj. [ModL < Gr thrombōsis, coagulation < thrombos, a clot: see THROMBUS]

thromboxane (-bäk´sein) •n. any of various derivatives of prostaglandins, which form on blood platelets and, usually, cause blood clots and constrict blood vessels Cf. PROSTACYCLIN [THROMB(O)- + OX(Y)-¹ + -ANE]

thrombus (θräm´bэs) pl. throm´bi' (-bai') •n. the fibrinous clot attached at the site of thrombosis [ModL < Gr thrombos, a clot < IE *dhrómbhos < base *dherebh-, to coagulate]

throne (θroun) •n. 1 the chair on which a king, cardinal, etc. sits on formal or ceremonial occasions: it usually is on a dais, covered with a canopy, and highly decorated 2 the power or rank of a king, etc.; sovereignty 3 a sovereign, ruler, etc. {orders from the throne} 4 [pl.] Christian Theol. the third highest order in the hierarchy of angels •vt., vi. throned, thron´ing to enthrone or be enthroned [ME trone < OFr or L: OFr trone < L thronus < Gr thronos, a seat < IE base *dher-, to hold, support > FIRM¹]

throng (θröŋ) •n. 1 a great number of people gathered together; crowd 2 a crowding together of people; crowded condition 3 any great number of things massed or considered together; multitude •vi. to gather together, move, or press in a throng •vt. 1 to crowd or press upon in large numbers 2 to crowd into; fill with a multitude SYN. CROWD¹ [ME < OE (ge)thrang (akin to Ger drang) < base of thringan, to press, crowd: for IE base see THRALL]

throstle (θräs´эl) •n. 1 [Now Chiefly Dial.] SONG THRUSH 2 any of various machines for spinning wool, etc. [from the humming sound it makes] [ME < OE, akin to Ger drossel < IE base *trozdos- > THRUSH¹]

throttle (θrät´ªl) •n. 1 [Rare] the throat or windpipe 2 a valve that regulates the flow of fluids; esp., a butterfly valve that controls the release of fuel vapor from a carburetor, or the control valve in a steam line: also throttle plate 3 the hand lever or pedal that controls this valve •vt. -tled, -tling [ME throtlen < throte, throat] 1 to choke; strangle 2 to stop the utterance or action of; censor or suppress 3 a) to reduce the flow of (fuel vapor, etc.) by means of a throttle b) to lessen the speed of (an engine, vehicle, etc.) by this or similar means; slow (down) •vi. to choke or suffocate throt´tler •n. [prob. dim. of THROAT: see -LE]

throttlehold (-hould') •n. power to restrict or prevent freedom of development, movement, etc.; stranglehold

through (θru:) •prep. 1 in one side and out the other side of; from end to end of 2 in the midst of; among 3 by way of 4 over the entire extent or surface of 5 to various places in; around {touring through France} 6 a) from the beginning to the end or conclusion of {to go through an experience, through the summer} Æ b) up to and including {through Friday} 7 without making a stop {to go through a red light} 8 past the limitations or difficulties of {to fight one's way through red tape} 9 by means of {through her help} 10 as a result of; because of {done through error} •adv. 1 in one side and out the other; from end to end 2 from the beginning to the end 3 completely to the end; to a conclusion {to see something through} 4 in every part or way; thoroughly; completely {soaked through}: also through and through •adj. 1 extending from one place to another; allowing free passage {a through street} Æ 2 a) traveling to the destination without stops {a through train} b) continuing on without making a stop {through traffic} Æ 3 not necessitating changes; good for traveling without intermediate transfer {a through ticket} 4 arrived at the end; finished {through with an assignment} 5 at the end of one's usefulness, resources, etc. {through in politics} 6 having no further dealings, connections, etc. (with someone or something) Through is also used in idiomatic expressions (e.g., get through), many of which are entered in this dictionary under the key words [ME thurgh, thrugh < OE thurh, akin to Ger durch < IE base *ter-, through, beyond > L trans, across, Sans tiráh, through]

throughly (θru:´li:) •adv. archaic var. of THOROUGHLY

throughout (θru: aut´) •prep. all the way through; in or during every part of •adv. 1 in or during every part; everywhere; from start to finish 2 in every respect

throughput (θru:´put') •n. the amount of material put through a process in a given period, as by a computer

throughway (θru:´wei') •n. alt. sp. of THRUWAY: see EXPRESSWAY

throve (θrouv) •vi. alt. pt. of THRIVE

throw (θrou) threw, thrown, throw´ing •vt. 1 to twist strands of (silk, etc.) into thread or yarn 2 to cause to fly through the air by releasing from the hand while the arm is in rapid motion; cast; hurl 3 to discharge through the air from a catapult, pump, gun, etc. 4 to hurl violently, as in anger, etc.; dash 5 to cause to fall; upset; overthrow; dislodge {thrown by a horse} 6 to move or send rapidly; advance {to throw reinforcements into a battle} 7 to put suddenly and forcibly into or onto {she threw the clothes into the suitcase} 8 to put suddenly and forcibly into a specified condition or situation {thrown into prison, into confusion, etc.} 9 a) to cast or roll (dice) b) to make (a specified cast) at dice {to throw a five} 10 to cast off; shed {snakes throw their skins, the horse threw its shoe} 11 to bring forth (young): said of domesticated animals 12 to move the lever of (a switch, clutch, etc.) or connect, disconnect, engage, etc. by so doing 13 a) to direct, cast, turn, project, etc. (variously with at, on, upon, over, toward, etc.) {to throw a glance, a light, a shadow, etc.} b) to deliver (a punch) 14 to cause (one's voice) to seem to come from some other source, as in ventriloquism 15 to put (blame on, influence into, obstacles before, etc.) Æ 16 [Colloq.] to lose (a game, race, etc.) deliberately, as by prearrangement Æ 17 [Colloq.] to give (a party, dance, etc.) Æ 18 [Colloq.] to have (a fit, tantrum, etc.) 19 [Colloq.] to confuse or disconcert {the question completely threw him} 20 Card Games to play or discard (a card) 21 Ceramics to shape on a potter's wheel •vi. to cast or hurl something •n. 1 the action of a person who throws; a cast 2 a cast of dice, or the numbers cast 3 the distance something is or can be thrown {a stone's throw} Æ 4 a) a spread or coverlet for draping over a bed, sofa, etc. b) a woman's light scarf or wrap 5 a) the motion of a moving part driven by a cam, eccentric, etc. b) the range of such a motion; travel; stroke 6 Geol. the amount of displacement at a fault 7 Wrestling a particular way or an instance of throwing an opponent Æ throw a monkey wrench into to stop or obstruct by direct interference; sabotage throw away 1 to rid oneself of; discard 2 to be wasteful of; waste; squander 3 to fail to make use of {throwing away his talents} 4 Theater to deliver (a line, speech, etc.) in a deliberately offhand manner throw back 1 to check or stop from advancing 2 to revert to an earlier or more primitive type or condition throw cold water on to discourage by indifference or disparagement throw in 1 to engage (a clutch) or cause (gears) to mesh 2 to add on without extra charge 3 to add to others 4 [Colloq.] to join (with) in cooperative action throw off 1 a) to rid oneself of; cast off b) to recover from c) Card Games to discard 2 a) to evade (a pursuer) b) to mislead c) to disconcert or confuse 3 to expel, emit, etc. 4 [Colloq.] to write or utter quickly, in an offhand manner throw on to put on (a garment) carelessly or hastily throw oneself at to try very hard to win the affection or love of throw oneself into to engage in with great vigor throw oneself on (or upon) to ask for (someone's mercy, etc.) for oneself throw open 1 to open completely and suddenly 2 to remove all restrictions from throw out 1 to get rid of; discard 2 to reject or remove, often with force 3 to emit 4 to put forth or utter (a hint or suggestion) 5 to disengage (a clutch) Æ 6 Baseball to throw the ball to a teammate who in turn retires (a runner) throw over 1 to give up; abandon 2 to forsake; jilt throw together 1 to make or assemble hurriedly and carelessly 2 to cause to become acquainted throw up 1 to give up or abandon 2 to raise suddenly or rapidly 3 to vomit 4 to construct rapidly Æ 5 to mention repeatedly (to someone), as in reproach or criticism throw´er •n. SYN.—throw is the general word meaning to cause to move through the air by a rapid propulsive motion of the arm, etc.; cast, the preferred word in certain connections [to cast a fishing line], generally has a more archaic or lofty quality [they cast stones at him]; to toss is to throw lightly or carelessly and, usually, with an upward or sideways motion [to toss a coin]; hurl and fling both imply a throwing with force or violence, but hurl suggests that the object thrown moves swiftly for some distance [to hurl a javelin] and fling, that it is thrust sharply or vehemently so that it strikes a surface with considerable impact [she flung the plate to the floor]; pitch implies a throwing with a definite aim or in a definite direction [to pitch a baseball] [ME throwen, to twist, wring, hurl < OE thrawan, to throw, twist, akin to Ger drehen, to twist, turn < IE base *ter-, to rub, rub with turning motion, bore > THRASH, THREAD, Gr teirein, L terere, to rub]

throw rug SCATTER RUG

throwaway (θrou´э wei') •n. a leaflet, handbill, etc. distributed as in the streets or from house to house •adj. Æ 1 designed to be discarded after use {a throwaway bottle} 2 delivered in a deliberately offhand manner, as a line of dialogue in a play 3 offhand; casual

throwback (θrou´bæk') •n. 1 [Now Rare] the act of throwing back; check, stop, or reversal 2 reversion to an earlier or more primitive type or condition 3 an instance or example of this

throwster (θrou´stэr) •n. a person whose work is making thread from silk or synthetic filaments [see THROW (vt. 1)]

throw-weight (θrou´weit') •n. the payload capacity of an ICBM: also throw weight

thru (θru:) •prep., adv., adj. colloq. sp. of THROUGH

thrum¹ (θrûm) •n. 1 a) the row of warp thread ends left on a loom when the web is cut off b) any of these ends 2 any short end thread or fringe 3 [pl.] Naut. short pieces of woolen or hempen yarn for thrumming canvas •vt. thrummed, thrum´ming 1 to provide with or make of thrums; fringe 2 Naut. to insert thrums in (canvas) to make a rough surface for preventing chafing, stopping leaks, etc. [ME < OE (in comp.), ligament, akin to Ger trumm < IE base *ter-, to pass over, cross > TRANS-, TERM]

thrum² (θrûm) thrummed, thrum´ming •vt. 1 to strum (a guitar, banjo, etc.) 2 to tell in a monotonous, tiresome way 3 to drum on with the fingers •vi. 1 a) to thrum a guitar, etc. b) to sound when so played 2 to drum with the fingers •n. a thrumming or the sound of this [echoic]

thrush¹ (θrûsh) •n. 1 any of a large family (Turdidae) of passerine birds, including the robin, wood thrush, and hermit thrush of North America and the song thrush and blackbird of Europe Æ 2 [Slang] a woman singer of popular songs [ME thrusch < OE thrysce < IE *trozdos-, thrush]

thrush² (θrûsh) •n. 1 a disease, esp. of infants, caused by a fungus (genus Candida) and characterized by the formation of milky-white lesions on the mouth, lips, and throat 2 a disease of the frog of a horse's foot, characterized by the formation of pus [< ON *thruskr (> Dan trøske, Swed torsk]

thrust (θrûst) thrust, thrust´ing •vt. 1 to push with sudden force; shove; drive 2 to pierce; stab 3 to force or impose (oneself or another) upon someone else or into some position or situation 4 to interject or interpose (a remark, question, etc.) 5 to extend, as in growth {the tree thrusts its branches high} •vi. 1 to push or shove against something 2 to make a thrust, stab, or lunge, as with a sword 3 to force one's way (into, through, etc.) 4 to extend, as in growth •n. 1 the act of thrusting; specif., a) a sudden, forceful push or shove b) a lunge or stab, as with a sword c) any sudden attack 2 continuous pressure of one part against another, as of a rafter against a wall 3 a) the driving force of a propeller in the line of its shaft b) the forward force produced in reaction to the gases escaping rearward from a jet or rocket engine 4 a) forward movement; impetus {the thrust of machine technology} b) energy; drive Æ 5 the basic meaning or purpose; point; force {the thrust of a speech} 6 Geol. an almost horizontal fault in which the hanging wall seems to have been pushed upward in relation to the footwall: in full thrust fault [ME thrusten, thristen < ON thrysta < IE *treud-, to squeeze, push > THREAT, L trudere]

thruster (θrûs´tэr) •n. 1 a person or thing that thrusts Æ 2 any of a set of maneuvering rockets on a spacecraft or high-altitude airplane, as for controlling its attitude for reentry

thruway (θru:´wei') •n. EXPRESSWAY

Thu Thursday

Thucydides (θu: sid´i di:z') c. 460-c. 400 B.C.; Athenian historian

thud (θûd) thud´ded, thud´ding •vi. to hit or fall with a dull sound •n. [prob. < the vi.] 1 a heavy blow 2 a dull sound, as that of a heavy, solid object dropping on a soft but solid surface [prob. < ME thudden, to strike, thrust < OE thyddan]

thug (θûg) •n. 1 [also T-] a member of a former group in India that murdered and robbed in the service of Kali 2 a rough, brutal hoodlum, gangster, robber, etc. thug´ger·y •n. thug´gish •adj. [Hindi thag, swindler < Sans sthaga, a cheat, rogue, akin to sthagayati, (he) hides < IE base *(s)teg-, to cover > THATCH]

thuggee (θûg´i:) •n. murder and robbery as formerly practiced by the thugs of India [Hindi thagī: see THUG]

thuja (θu:´jэ, θyu:´-) •n. ARBORVITAE (sense 1) [ModL < Gr thyia, Afr tree with aromatic wood]

Thule (for 1 θu:´li:, θyu:´-; tu:´-, tyu:´-; for 2 tu:´li:) 1 among the ancients, the northernmost region of the world, possibly taken to be Norway, Iceland, Jutland, etc.: also ul·ti·ma Thu·le (ûl´tэ mэ) 2 Eskimo settlement on the NW coast of Greenland: pop. c. 1,000: site of U.S. air base [L < Gr Thoulē, Thylē]

thulia (θu:´li: э, θyu:´-) •n. thulium oxide, Tm2O3 [ModL: so named (1879) by P. T. Cleve (see HOLMIUM) < Thule, Scandinavia: see THULE]

thulium (θu:´li: эm, θyu:´-) •n. a bright, silvery chemical element of the rare-earth metals: symbol, Tm; at. wt., 168.934; at. no., 69; sp. gr., 9.33; melt. pt., 1,545°C; boil. pt., 1,970°C [ModL: so named (1886) by L. de Boisbaudran (see GADOLINIUM) < prec. (from which it was isolated by Cleve in 1879) + -IUM]

thumb (θûm) •n. 1 the short, thick digit of the human hand that is nearest the wrist and is opposable to the other fingers 2 a corresponding part in some other vertebrate animals 3 the part of a glove or mitten that covers the thumb 4 Archit. OVOLO •vt. 1 to handle, turn, soil, or wear with or as with the thumb 2 [Colloq.] to solicit or get (a ride) or make (one's way) in hitchhiking by gesturing with the thumb extended in the direction one is traveling all thumbs clumsy; fumbling Æ thumb one's nose 1 to raise one's thumb to the nose with the fingers extended, as a coarse gesture of defiance or contempt 2 to express defiance or contempt thumbs down a signal of rejection or disapproval thumbs up a signal of acceptance or approval thumb through to glance rapidly through (a book), as by releasing or turning pages along their edge with the thumb under someone's thumb under someone's influence or sway thumb´less •adj. [ME (with unhistoric -b) < OE thuma, akin to Ger daume(n) < IE base *tēu-, to swell, increase > L tumor: basic sense, enlarged finger]

thumb index an index to the sections or divisions of a reference book, consisting of a series of rounded notches cut in the fore edge of a book with a labeled tab at the base of each notch thumb´-in´dex •vt.

thumb piano 1 KALIMBA 2 MBIRA

thumbnail (θûm´neil') •n. the nail of the thumb •adj. very small, brief, or concise {a thumbnail sketch}

thumbscrew (θûm´skru:') •n. 1 a screw with a head shaped in such a way that it can be turned with the thumb and forefinger 2 a former instrument of torture for squeezing the thumbs

thumbstall (θûm´stöl') •n. a kind of thimble or protective sheath, as of leather or rubber, for the thumb

thumbtack (θûm´tæk') •n. a tack with a wide, flat head that can be pressed into a board, etc. with the thumb

Thummim (θûm´im) •n. see URIM AND THUMMIM [Heb tummīm, pl. of tōm, perfection]

thump (θûmp) •n. 1 a blow with something heavy and blunt, as with a cudgel 2 the dull sound made by such a blow •vt. 1 to strike with a thump or thumps 2 a) to thrash; beat severely b) to defeat decisively •vi. 1 to hit or fall with a thump 2 to make a dull, heavy sound; pound; throb thump´er •n. [echoic]

thumping (θûmp´iŋ) •adj. 1 that thumps 2 [Colloq.] very large; whopping thump´ing·ly •adv.

Thun (tu:n) 1 city in central Switzerland, on the Aar River where it leaves the Lake of Thun: pop. 37,000 2 Lake of lake in Bern canton, central Switzerland: c. 18 sq. mi. (46 sq. km)

thunder (θûn´dэr) •n. 1 the sound that follows a flash of lightning, caused by the sudden heating and expansion of air by electrical discharge 2 any loud, rumbling sound like this 3 a threatening, menacing, or extremely vehement utterance 4 [Archaic] a thunderbolt Also used in mild oaths and imprecations [yes, by thunder!; where in thunder is he?] Also thun'der·a´tion •vi. 1 to produce thunder: usually in the impersonal construction [it is thundering] 2 to make, or move with, a sound like thunder 3 to make vehement speeches, denunciations, etc. •vt. 1 to say in a thundering voice 2 to strike, drive, etc. with the sound or violence of thunder steal someone's thunder to use someone's ideas or methods without permission and without giving credit; esp., to lessen the effectiveness of someone's statement or action by anticipating that person in its use thun´der·er •n. [ME thuner, thunder (with unhistoric -d-) < OE thunor, akin to Ger donner < IE base *(s)ten-, loud rustling, deep noise > ON Thorr, THOR, Gr stenein, to moan, L tonare, to thunder]

Thunder Bay city & port in W Ontario, Canada, on Lake Superior: formed in 1970 by the merger of Fort William and Port Arthur: pop. 118,000 [after the bay on which it is located: the bay was named for the thunderbird of Indian legend]

thunderbird (θûn´dэr børd') •n. Æ in the mythology of certain North American Indians, an enormous bird that produces thunder, lightning, and rain

thunderbolt (-boult') •n. 1 a flash of lightning and the accompanying thunder 2 a bolt or missile imagined as hurled to earth by a stroke of lightning 3 something that stuns or acts with sudden violence or force

thunderclap (-klæp') •n. 1 a clap, or loud crash, of thunder 2 anything like this in being sudden, startling, violent, etc. Also thun´der·peal' (-pi:l')

thundercloud (-klaud') •n. a storm cloud charged with electricity and producing lightning and thunder

thunderegg (-eg') •n. a cryptocrystalline variety of quartz, often found in egg-shaped nodules [< ?]

thunderhead (-hed') •n. a round mass of cumulus clouds appearing before a thunderstorm

thundering (θûn´dэr iŋ) •adj. 1 that thunders 2 [Colloq.] very large; thumping; whopping thun´der·ing·ly •adv.

thunderous (θûn´dэr эs) •adj. 1 full of or making thunder 2 making a noise like thunder thun´der·ous·ly •adv.

thundershower (θûn´dэr shau'эr) •n. a shower accompanied by thunder and lightning

thundersquall (-skwöl') •n. a squall accompanied by thunder and lightning

thunderstone (-stoun') •n. any of various stones, fossils, prehistoric implements, etc. formerly thought to have been hurled to earth by lightning and thunder

thunderstorm (-störm') •n. a storm accompanied by thunder and lightning

thunderstruck (-strûk') •adj. struck with amazement, terror, etc., as if by a thunderbolt: also thun´der·strick'en (-strik'эn)

thundery (θûn´dэr i:) •adj. 1 that sounds like thunder 2 accompanied with or betokening thunder

thunk (θûŋk) •n. an abrupt, muffled sound, as of an ax hitting a tree trunk •vi. to make such a sound [echoic]

Thur Thursday

Thurber (θør´bэr), James (Grover) 1894-1961; U.S. writer, humorist, & cartoonist

Thurgau (tur´gau') canton of NE Switzerland, on Lake Constance: 388 sq. mi. (1,005 sq. km); pop. 183,000: Fr. name Thur·go·vie (tüř gô vi:´)

thurible (θør´э bэl; θur´-, θyur´-) •n. CENSER [ME thoryble < L thuribulum < thus (gen. thuris), frankincense < Gr thyos, incense < thyein: see THYME]

thurifer (-э fэr) •n. an acolyte or altar boy who carries a thurible [ModL < L thus (see THURIBLE) + ferre, BEAR¹]

Thuringer (θu: rin jэr, tir-) •n. any of several types of fresh or smoked, lightly seasoned sausage

Thuringia (θu: rin´ji: э, θyu:-; -jэ) state of central Germany: 5,985 sq. mi. (15,500 sq. km); pop. 2,500,000; cap. Erfurt: Ger. name Thü·ring·en (tü´řiŋ эn)

Thuringian (θu: rin´ji: эn, -jэn) •adj. of Thuringia, its people, or culture •n. 1 a member of an ancient Germanic people of central Germany 2 a native or inhabitant of Thuringia

Thuringian Forest forested mountain range in Thuringia, Germany: highest peak, 3,222 ft.: Ger. name Thü·ring·er Wald (tü'řiŋ эř vält´)

Thurs Thursday

Thursday (θørz´dei; also, -di:) •n. the fifth day of the week: abbrev. Thur, Thurs, Thu, Th, or T [ME Thoresdai, Thunres dai < OE Thunres dæg, ON Thorsdagr, Thor's day, rendering LL Jovis dies] Thursday Australian island in Torres Strait: 1.25 sq. mi. (3.23 sq. km)

Thursdays (θørz´deiz; also, -di:z) •adv. during every Thursday or most Thursdays

thus (ðûs) •adv. 1 in this or that manner; in the way just stated or in the following manner 2 to this or that degree or extent; so 3 according to this or that; consequently; therefore; hence: often used with conjunctive force 4 for example [ME < OE]

thusly (-li:) •adv. [Colloq.] THUS (sense 1)

thwack (θwæk) •vt. to strike with something flat; whack •n. a blow with something flat [prob. echoic]

thwart (θwört) •adj. 1 lying or extending across something else; transverse; oblique 2 [Obs.] perverse •adv., prep. archaic var. of ATHWART •n. 1 a rower's seat extending across a boat 2 a brace extending across a canoe •vt. 1 orig., to extend or place over or across 2 to hinder, obstruct, frustrate, or defeat (a person, plans, etc.) SYN. FRUSTRATE [ME thwert < ON thvert, neut. of thverr, transverse < IE *terk-, to turn (prob. < *ter-, to rub with rotary motion > THROW) > L torquere, to twist, turn]

thy (ðai) possessive pronominal adj. of, belonging to, or done by thee: archaic or poetic var. of your: see also THINE, THOU¹ [ME thi, contr. < thin, thy: see THINE]

Thyestean banquet (or feast) (θai es´ti: эn, θai'es ti:´эn) a banquet at which human flesh is served [in allusion to the Greek tale that after Thyestes seduced Atreus' wife, Atreus murdered Thyestes' sons and served them to him at a feast]

Thyestes (θai es´ti:z') Gr. Myth. a brother of Atreus and son of Pelops See ATREUS [L < Gr Thyestēs]

thylacine (θai´lэ sain', -sin) •n. TASMANIAN WOLF [Fr < Gr thylax, pouch]

thyme (taim) •n. 1 any of a genus (Thymus, esp. T. vulgaris) of shrubby plants or aromatic herbs of the mint family, with white, pink, or red flowers and with fragrant leaves 2 the leaves, used as an herb for seasoning [ME < MFr thym < L thymum < Gr thymon < thyein, to sacrifice, smoke < IE base *dheu- > DULL]

thymic (θai´mik) •adj. of the thymus

thymidine (θai´mэ di:n', -din) •n. a crystalline nucleoside, C10H14N2O5, one of the basic components of DNA: used chiefly in biochemical research [< fol. + -ID(E) + -INE³]

thymine (θai´mi:n', -min) •n. a white, crystalline, pyrimidine base, C5H6N2O2, contained in the nucleic acids of all tissue: it links with adenine in the DNA structure [Ger thymin < Gr thymos, spirit (< IE *dhūmo- < base *dheu-, to blow > DULL, FUME) + Ger -in, -INE³]

thymol (θai´möl', -moul') •n. a colorless, crystalline phenol, C10H14O, extracted from the volatile oil of thyme or made synthetically: used as an antiseptic, esp. in mouthwashes and nose and throat sprays, and in perfumery, embalming, microscopy, etc. [THYM(E) + -OL¹]

thymosin (θai´mэ sin) •n. any of a group of hormones, secreted by the thymus, that stimulate the immune system by helping T cells mature [< Gr thymos, THYMUS + -IN¹]

thymus (θai´mэs) •n. a gland in the upper thorax or neck of all vertebrates, involved in the production of lymphocytes: in humans, it is most prominent at puberty, after which it disappears or becomes vestigial: also thymus gland [ModL < Gr thymos, orig., a warty excrescence]

thyratron (θai´rэ trän') •n. a hot-cathode, triode or tetrode, electronic tube containing low-pressure gas or metal vapor in which one or more electrodes start the current flow but exercise no further control over its flow [< Gr thyris, window, cell + -a- + -TRON]

thyristor (θai ris´tэr) •n. any of various solid-state, semi-conductor devices that convert alternating current to a unidirectional current; specif., a silicon-controlled rectifier [Gr thyris, window, cell (akin to thyra, DOOR) + -tor, as in RESISTOR]

thyro- (θai´rou, -rэ) combining form thyroid {thyrotoxicosis}: also, before a vowel, thyr-

thyrocalcitonin (θai'rou kæl'si tou´nin) •n. CALCITONIN [prec. + CALCI- + TON(E) + -IN¹]

thyroid (θai´roid') •adj. 1 designating or of a large ductless gland lying in front and on either side of the trachea and secreting the hormone thyroxine, which regulates body growth and metabolism: the malfunctioning or congenital absence of this gland can cause goiter, cretinism, etc. 2 designating or of the principal cartilage of the larynx, forming the Adam's apple •n. 1 the thyroid gland 2 the thyroid cartilage 3 an artery, nerve, etc. in the region of the thyroid 4 a preparation of the thyroid gland of certain animals, used in treating goiter, myxedema, etc.: also thyroid extract [ModL thyroides < Gr thyreoeidēs, shield-shaped < thyreos, large shield, door-shaped shield < thyra, DOOR + -eidēs, -OID]

thyroidectomy (θai'roi dek´tэ mi:) pl. -mies •n. the surgical removal of all or part of the thyroid gland

thyroiditis (-dait´is) •n. inflammation of the thyroid gland [ModL: see -ITIS]

thyrotoxicosis (θai'rou täks'i kou´sis) •n. HYPERTHYROIDISM [THYRO- + TOXICOSIS]

thyrotropin (θai rä´trэ pin) •n. a hormone isolated from the anterior pituitary that stimulates the production of thyroxine in the thyroid: also thy·rot´ro·phin (-fin) [THYRO- + TROP(HIC) + -IN¹]

thyroxine (θai räks´i:n', -in) •n. a colorless, crystalline compound, C15H11I4NO4, the active hormone of the thyroid gland, often prepared synthetically and used in treating goiter, cretinism, and myxedema: also thy·rox´in (-in) [THYR(O)- + OX(Y)-¹ + -INE³]

thyrsus (θør´sэs) pl. -si' (-sai') •n. 1 a staff tipped with a pine cone and sometimes entwined with ivy or vine leaves, which Dionysus, the satyrs, etc. were represented as carrying 2 Bot. a flower cluster in which the main stem is racemose and the secondary stems are cymose, as in the lilac: also thyrse (θørs) [L < Gr thyrsos; ? akin to Hittite tuwarsa-, grape vine]

thysanuran (θai'sэ nyur´эn, -nur´-; θis'-) •n. any of an order (Thysanura) of very primitive insects that have bristlelike appendages at the rear end, including bristletails and silverfish [< ModL Thysanura (< Gr thysanos, tassel + oura, a tail) + -AN]

thyself (ðai self´) pron. reflexive or intensive form of THOU¹: an archaic or old poet. var. of yourself [ME thi self, superseding earlier the self, lit., thee self < OE the self; in ME, self, orig. adj., was regarded as n.]

Ti 1 Bible Timothy 2 Chem. symbol for titanium 3 Bible Titus

ti¹ (ti:) •n. Music a syllable representing the seventh tone of the diatonic scale: see SOLFEGGIO [altered < si: see GAMUT]

ti² (ti:) •n. a Polynesian and Australian woody plant (genus Cordyline) of the agave family: the leaves are used for thatch, garments, fodder, etc., and the roots are used for food and liquor [< a Polynesian language, e.g. Maori or Samoan: ult. < Proto-Polynesian *tii]

TIA (ti:'ai'ei´) •n. a mild cerebrovascular stroke with reversible symptoms that last from a few minutes to several hours [T(ransient) I(schemic) A(ttack)]

Tia Juana (ti:'э wän´э, -hwän´э; Sp ti:'ä hwä´nä) old name of TIJUANA

Tian Shan (tyen shän´) mountain system in central Asia, extending across Kyrgyzstan & Xinjiang, China, to the Altai Mountains: highest peak, 24,406 ft. (7,450 m)

Tianjin (tyen jin´) seaport in NE China: capital of Hebei province: pop. 5,100,000

tiara (ti: er´э, -ær´-, -är´-; tai-) •n. 1 a headdress of the ancient Persians 2 the pope's triple crown 3 a woman's crownlike headdress of jewels or flowers; coronet [L < Gr: prob. of Oriental orig.]

Tiber (tai´bэr) river in central Italy, flowing from the Apennines south through Rome into the Tyrrhenian Sea: c. 250 mi. (402 km): It. name TEVERE [L Tiberis]

Tiberias (tai bir´i: эs), Sea of Sea of GALILEE

Tiberius (tai bir´i: эs) (Tiberius Claudius Nero Caesar) 42 B.C.-A.D. 37; Rom. emperor (A.D. 14-37)

Tibesti (ti bes´ti:) mountain group of the Sahara, mostly in NW Chad: highest peak, 11,204 ft. (3,414 m)

Tibet (ti bet´) autonomous region of SW China, occupying a high plateau area north of the Himalayas: 471,660 sq. mi. (1,221,000 sq. km); pop. 1,892,000; cap. Lhasa

Tibetan (ti bet´ªn) •adj. of Tibet, its people, their language, or culture •n. 1 a member of a Mongolian people native to Tibet 2 the Tibeto-Burman language of this people 3 any native or inhabitant of Tibet

Tibetan spaniel any of a breed of small, spaniel-type dog, originating in Tibet, with a blunt muzzle, short legs, and a plumed tail curled over the back, usually kept as a pet

Tibetan terrier any of a breed of small dog, originating in Tibet, with a profuse coat of long hair falling over the eyes and a tail that curls over the back

Tibeto-Burman (ti bet'ou bør´mэn) •n. a branch of the Sino-Tibetan family of languages, including Tibetan and Burmese •adj. designating or of this group of languages or the peoples speaking them

tibia (tib´i: э) pl. -i·ae' (-i: i:') or -i·as •n. 1 the inner and thicker of the two bones of the human leg between the knee and the ankle; shinbone: see SKELETON, illus. 2 a corresponding bone in the leg of other vertebrates 3 the fourth segment (from the base) of an insect's leg 4 an ancient flute, orig. made from an animal's tibia tib´i·al •adj. [L < ?]

Tibur (tai´bэr) ancient name of TIVOLI (Italian city)

tic (tik) •n. 1 any involuntary, regularly repeated, spasmodic contraction of a muscle, generally of neurotic origin 2 short for TIC DOULOUREUX [Fr < ?]

tic douloureux (tik' du:'lu ru:´; Fr ti:k du: lu: řö´) TRIGEMINAL NEURALGIA [Fr, lit., painful tic]

Ticino (ti: chi:´nou) 1 canton of S Switzerland, on the Italian border: 1,085 sq. mi. (2,811 sq. km); pop. 265,000 2 river flowing from this canton south into the Po River: c. 160 mi. (258 km)

tick fever any infectious disease transmitted by the bite of a tick, as Rocky Mountain spotted fever

tick trefoil any of a genus (Desmodium) of leguminous plants with clusters of small purple flowers, leaves in groups of three, and jointed prickly pods

tick¹ (tik) •n. 1 orig., a light touch; pat 2 a light clicking or tapping sound, as that made by the escapement of a watch or clock 3 a mark made to check off items; check mark (√, /, etc.) 4 [Brit., etc. Colloq.] moment; instant [from the time needed for one tick of a clock] •vi. 1 to make a tick or series of ticks, as a clock 2 [Colloq.] to function characteristically or well; operate; work {what makes him tick?} •vt. 1 to indicate, record, or count by a tick or ticks 2 [Chiefly Brit., etc.] to mark or check off (an item on a list, etc.) with a tick: usually with off tick off 1 [Brit., etc. Colloq.] to reprimand 2 [Slang] to make angry or irritable [ME tek, prob. < Gmc echoic base > Du tikk, MHG zicken, to tick]

tick² (tik) •n. 1 any of a superfamily (Ixodoidea, order Parasitiformes) of wingless, bloodsucking mites, including many species that transmit diseases and are usually parasitic on humans, cattle, sheep, etc. 2 any of various degenerate, two-winged, parasitic insects [ME teke < OE ticia (? for ticca), akin to MDu teke, Ger zecke < IE base *deiGh-, to prickle, itch > Arm tiz, tick, MIr dega, stag beetle]

tick³ (tik) •n. 1 the cloth case or covering that is filled with cotton, feathers, hair, etc. to form a mattress or pillow 2 [Colloq.] TICKING [LME tykke, akin to MDu tyke, both prob. < early WGmc borrowing < L theca, a cover, sheath: see THECA]

tick4 (tik) •n. [Colloq., Chiefly Brit., etc.] credit; trust {to buy something on tick} [contr. < TICKET]

ticker (tik´эr) •n. a person or thing that ticks; specif., Æ a) a telegraphic device for recording stock market quotations, etc. on a paper tape b) an electronic device for displaying stock market quotations c) [Old Slang] a watch d) [Slang] the heart

ticker tape paper tape used in a TICKER (sense a) for recording telegraphed stock market quotations, etc.

ticket (tik´it) •n. 1 orig., any note, memorandum, voucher, etc. 2 a printed card or piece of paper that gives a person a specified right, as to attend a theater, ride on a train, claim a purchase, etc. 3 a license or certificate, as of a ship's captain or an airplane pilot 4 a label or tag, as on a piece of merchandise, giving the size, color, price, quantity, etc. Æ 5 the list of candidates nominated by a political party in an election; slate Æ 6 [Colloq.] a summons to court for a traffic violation •vt. 1 to label or tag with a ticket 2 to provide a ticket or tickets for Æ 3 [Colloq.] to issue or attach a TICKET (n. 6) to that's the ticket! [Slang] that's the correct or proper thing! that's right! [aphetic < obs. Fr etiquet (now étiquette)]

ticket-of-leave man (tik'it эv li:v´) [Brit.] a convicted person whose sentence had not expired, set conditionally at liberty by issuance of a revocable permit (ticket of leave)

tickety-boo (tik´i ti: bu:´) •adj. [Brit. Colloq.] fine, excellent, in working order, etc.: an old-fashioned use [< TICKET (as in THAT'S THE TICKET!) + -Y¹ + -boo]

ticking (tik´iŋ) •n. strong, heavy cloth, often striped, used for casings of mattresses, pillows, etc. [see TICK³]

tickle (tik´эl) -led, -ling •vt. 1 to please, gratify, delight, etc.: often used in the passive voice with slang intensives, as tickled pink, tickled silly, tickled to death, etc. 2 to stir to amusement or laughter; amuse 3 to excite the surface nerves of, as by touching or stroking lightly with the finger, a feather, etc., so as to cause involuntary twitching, a pleasant tingling, laughter, etc. •vi. 1 to have an itching, scratching, or tingling sensation {a throat that tickles} 2 to cause a tickling sensation {that feather tickles} 3 to be readily affected by excitation of the surface nerves; be ticklish •n. 1 a tickling or being tickled 2 a tickling sensation [ME tikelen, akin to Ger dial. zickeln, OE tinclian, to tickle: for IE base see TICK²]

tickler (tik´lэr, -эl эr) •n. 1 a person or thing that tickles Æ 2 a special memorandum pad, file, etc. for reminding one of matters requiring attention at certain dates in the future

tickler coil a small coil connected in series with the plate circuit of a vacuum tube and coupled inductively to the grid circuit to furnish feedback

ticklish (tik´lish, -эl ish) •adj. 1 sensitive to tickling 2 very sensitive or easily upset; touchy 3 needing careful handling; precarious; delicate tick´lish·ly •adv. tick´lish·ness •n.

tickseed (tik´si:d') •n. 1 COREOPSIS 2 BUR MARIGOLD [TICK² + SEED: from the appearance]

ticktack or tictac (tik´tæk') •n. 1 a recurring sound like the ticking of a clock 2 a device for making a tapping sound on a windowpane or door as a prank: it consists typically of a weight hung next to the window, etc. and manipulated from a distance by a string [echoic redupl. of TICK¹]

tick-tack-toe or tic-tac-toe (tik'tæk tou´) •n. a game in which two players take turns marking either X's or O's in an open block of nine squares, the object being to complete a vertical, horizontal, or diagonal row of three of one's mark before the other player can

ticktock (tik´täk') •n. the ticking sound made by a clock •vi. to make this sound

ticky tacky (tik´i: tæk´i:) dull, unimaginative, often shoddy uniformity, like that of houses in some less expensive real-estate developments tick´y-tack'y •adj. [redupl. of TACKY²]

Ticonderoga (tai kän'dэr ou´gэ, tai'kän-), Fort former fort in NE N.Y., taken from the British by the Green Mountain Boys in 1775 [Mohawk tekontaró:ken, lit., at the junction of two waterways]

tidal (taid´ªl) •adj. of, having, caused by, determined by, or dependent on a tide or tides tid´al·ly •adv.

tidal wave 1 nontechnical term for a tsunami or a similar wave caused by strong winds and not actually related to the tides Æ 2 any great or widespread movement, expression of prevalent feeling, etc.

tidbit (tid´bit') •n. a pleasing or choice bit of food, news, gossip, etc. [dial. tid, small object + BIT²]

tiddly¹ (tid´li:, tid´ªl i:) •adj. [Colloq., Chiefly Brit., etc.] drunk; tipsy [prob. < tiddly-wink, illicit grogshop, rhyming slang for DRINK]

tiddly² (tid´li:) •adj. [Brit., etc.] very small; little [prob. < child's alteration of little]

tiddlywinks (tid´li: wiŋks', tid´ªl i:-) •n.pl. [with sing. v.] a game in which the players try to snap little colored disks from a surface into a cup by pressing their edges with a larger disk Also tid´dle·dy·winks' (-ªl di: wiŋks') [prob. < tiddly, child's form of LITTLE: cf. TIDDLY¹]

tide rip a rip current associated with a tidal current

tide¹ (taid) •n. 1 orig., a period of time: now only in combination {Eastertide, eventide} 2 a) the alternate rise and fall of the surface of oceans, seas, and the bays, rivers, etc. connected with them, caused by the attraction of the moon and sun: it may occur twice in each period of 24 hours and 50 minutes, which is the time of one rotation of the earth with respect to the moon (see also FLOOD TIDE, SPRING TIDE) b) FLOOD TIDE [prob. infl. by MLowG or MDu] 3 something that rises and falls like the tide 4 a stream, current, etc. or trend, tendency, etc. {the tide of public opinion} 5 the period during which something is at its highest or fullest point 6 [Archaic] an opportune time or occasion •adj. TIDAL •vi. tid´ed, tid´ing 1 to flow or surge like a tide 2 Naut. to drift with the tide, esp. in moving into or out of a harbor, river, etc. •vt. to carry with or as with the tide tide over to help along temporarily, as through a period of difficulty turn the tide to reverse a condition [ME, tide, time, season < OE tid, time; akin to Ger zeit < IE *dī-, var. of base *da(i)-, to part, divide up > TIME, Sans dāti, (he) cuts off, Gr dēmos, district, people]

tide² (taid) tid´ed, tid´ing •vt. [Archaic] to betide; happen [ME tiden < OE tidan < tid: see TIDE1]

tideland (-lænd', -lэnd) •n. 1 land covered by water at high tide and uncovered at low tide 2 [pl.] loosely, land under water just beyond this and within territorial limits

tidemark (-märk') •n. a mark indicating the highest point of flood tide or, sometimes, the lowest point of ebb tide

tidewaiter (-weit'эr) •n. [Historical] a customs official who boarded incoming ships to prevent customs evasion

tidewater (taid´wöt'эr) •n. 1 water brought into an area by the action of the rising tide Æ 2 water that is affected by the tide, as a stream along a coastline Æ 3 an area in which water is affected by the tide Æ 4 [T-] the English dialect of E Virginia •adj. 1 of or along a tidewater Æ 2 [T-] of (the) Tidewater [T-] the eastern part of Virginia

tideway (-wei') •n. 1 a channel through which a tide runs 2 the tidal part of a river 3 a tidal current

tidings (taid´iŋz) •n.pl. news; information [ME, pl. of tidinge < OE tidung (< tidan: see TIDE²); akin to Ger zeitung, newspaper]

tidy (taid´i:) -di·er, -di·est •adj. 1 neat in personal appearance, ways, etc.; orderly 2 neat in arrangement; in order; trim 3 [Colloq.] a) fairly good; satisfactory b) rather large; considerable {a tidy sum of money} •vt., vi. -died, -dy·ing to make (things) tidy Often with up •n. pl. -dies 1 ANTIMACASSAR 2 a small container for odds and ends ti´di·ly •adv. ti´di·ness •n. [ME tidi, seasonable, honest, hence in good condition < tide: see TIDE¹]

tidytips (tai´di: tips') pl. -tips' •n. a California wildflower (Layia platyglossa) of the composite family, with yellow, daisylike flowers, often tipped with white

tie (tai) tied, ty´ing or tie´ing •vt. 1 to fasten, attach, or bind together or to something else, as with string, cord, or rope made secure by knotting, etc. {to tie someone's hands, to tie a boat to a pier} 2 a) to draw together or join the parts, ends, or sides of by tightening and knotting laces, strings, etc. {to tie one's shoes} b) to make by fastening together parts {to tie fishing flies} 3 a) to make (a knot or bow) b) to make a knot or bow in {to tie one's necktie} 4 to fasten, connect, join, or bind in any way {tied by common interests} 5 to confine; restrain; restrict 6 a) to equal the score or achievement of, as in a contest b) to equal (a score, record, etc.) 7 [Colloq.] to join in marriage 8 Music to connect with a tie •vi. 1 to be capable of being tied; make a tie 2 to make an equal score or achievement, as in a contest •n. [ME tege, teige < OE teag, teah, a rope] 1 a string, lace, cord, etc. used to tie things 2 something that connects, binds, or joins; bond; link {a business tie, ties of affection} 3 something that confines, limits, or restricts {legal ties} 4 short for NECKTIE 5 a beam, rod, etc. that holds together parts of a building and strengthens against stress Æ 6 any of the parallel crossbeams to which the rails of a railroad are fastened 7 a) an equality of scores, votes, achievement, etc. in a contest b) a contest or match in which there is such an equality; draw; stalemate 8 [pl.] low shoes fastened with laces, as oxfords 9 Music a curved line above or below two notes of the same pitch, indicating that the tone is to be held unbroken for the duration of their combined values •adj. that has been tied, or made equal {a tie score} tie down to confine; restrain; restrict Æ tie in 1 to bring into or have a connection 2 to make or be consistent, harmonious, etc. Æ tie into [Colloq.] to attack vigorously tie off 1 to make (a rope or line) fast 2 to close off passage through by tying with something Æ tie one on [Slang] to get drunk tie up 1 to tie firmly or securely 2 to wrap up and tie with string, cord, etc. 3 to moor (a ship or boat) to a dock Æ 4 to obstruct; hinder; stop 5 to cause to be already in use, retained, committed, etc. SYN.—tie and bind are often interchangeable, but in discriminating use, tie specif. implies the connection of one thing with another by means of a rope, string, etc. which can be knotted [to tie a horse to a hitching post], and bind suggests the use of an encircling band which holds two or more things firmly together [to bind someone's legs]; fasten, a somewhat more general word, implies a joining of one thing to another, as by tying, binding, gluing, nailing, pinning, etc.; attach emphasizes the joining of two or more things in order to keep them together as a unit [to attach one's references to an application] —ANT. separate, part [ME tien < OE tigan, tegan; akin to teag, a rope: for IE base see TOW¹]

tie beam a horizontal beam serving as a TIE (n. 5): see FRAME, illus.

tie clasp a decorative clasp for fastening a necktie to the shirt front: also tie clip or tie bar

tie line Æ 1 a direct telephone line between extensions in two or more PBX systems Æ 2 a line used to connect one electric power or transportation system with another

tie rod 1 a horizontal rod serving as a TIE (n. 5) 2 a rod that connects certain parts in the steering linkage of a motor vehicle

tie tack or tie tac an ornamental pin with a short point that fits into a snap, used to fasten a necktie to the shirt front

tieback (tai´bæk') •n. Æ 1 a fabric strip, ribbon, tape, etc. used to tie curtains or draperies to one side Æ 2 a curtain with a tieback: usually used in pl.

tiebreaker (tai´breik'эr) •n. 1 an additional game, period of play, question, etc. used to establish a winner from among those tied at the end of a contest 2 Tennis any of several forms of play sometimes used to decide the winner of a set tied at a certain score