A- (3) prefix meaning "not," from Gk a-, an- "not," from pie base *ne "not" (see un-)

thing --- O.E. þing "meeting, assembly," later "entity, being, matter" (subject of deliberation in an assembly), also "act, deed, event, material object, body, being," from P.Gmc. *thengan "appointed time" (cf. O.Fris. thing "assembly, council, suit, matter, thing," M.Du. dinc "court-day, suit, plea, concern, affair, thing," Du. ding "thing," O.H.G. ding "public assembly for judgment and business, lawsuit," Ger. ding "affair, matter, thing," O.N. þing "public assembly"). Some suggest an ultimate connection to PIE root *ten- "stretch," perhaps on notion of "stretch of time for a meeting or assembly." For sense evolution, cf. Fr. chose, Sp. cosa "thing," from L. causa "judicial process, lawsuit, case;" L. res "affair, thing," also "case at law, cause." Old sense is preserved in second element of hustings and in Icelandic Althing, the nation's general assembly. Southern U.S. pronunciation thang attested from 1937. The thing "what's stylish or fashionable" is recorded from 1762. Phrase do your thing "follow your particular predilection," though associated with hippie-speak of 1960s is attested from 1841. Used colloquially since 1602 to indicate things the speaker can't name at the moment, often with various meaningless suffixes, e.g. thingumbob (1751), thingamajig (1824).

think --- O.E. þencan "conceive in the mind, think, consider, intend" (past tense þohte, p.p. geþoht), probably originally "cause to appear to oneself," from P.Gmc. *thankjan (cf. O.Fris. thinka, O.S. thenkian, O.H.G. denchen, Ger. denken, O.N. þekkja, Goth. þagkjan); O.E. þencan is the causative form of the distinct O.E. verb þyncan "to seem or appear" (past tense þuhte, pp. geþuht), from P.Gmc. *thunkjan (cf. Ger. dünken, däuchte). Both are from PIE *tong- "to think, feel" which also is the root of thought and thank. The two meanings converged in M.E. and þyncan "to seem" was absorbed, except for archaic methinks "it seems to me." Jocular pp. thunk (not historical, but by analogy of drink, sink, etc.) is recorded from 1876. Think-tank is 1959 as "research institute" (first ref. is to Center for Behavioral Sciences, Palo Alto, Calif.); it had been colloquial for "the brain" since 1905.

thinner --- liquid used to dilute paint, ink, etc., 1904, from thin.

third (adj.) --- O.E. metathesis of þridda, from P.Gmc. *thridjas (cf. O.Fris. thredda, O.S. thriddio, M.L.G. drudde, Du. derde, O.H.G. dritto, Ger. dritte, O.N. þriðe, Goth. þridja), from PIE *tritjos (cf. Skt. trtiyas, Avestan thritya, Gk. tritos, L. tertius, O.C.S. tretiji, Lith. trecias, O.Ir. triss). Related to O.E. þreo (see three). Metathesis of thrid into third is attested from c.950 in Northumbria, but thrid was prevalent up to 16c. The noun meaning "third part of anything" is recorded from 1382. Third rail in electric railway sense is recorded from 1890. Third World War as a possibility first recorded 1947. Third-rate "of poor quality" is from 1814, ult. from classification of ships (1649); third class in railway travel is from 1839. Third Reich (1930) is a partial transl. of Ger. drittes Reich (1923). Third party in law, insurance, etc., is from 1818.

third degree --- intense interrogation by police, 1900, probably a reference to Third Degree of master mason in Freemasonry (1772), the conferring of which included an interrogation ceremony. Third degree as a measure of severity of burns (most severe) is attested from 1866, from Fr. (1832); in Amer.Eng., as a definition of the seriousness of a particular type of crime (the least serious type) it is recorded from 1865.

Third World --- 1963, from Fr. tiers monde, formulated 1952 by A. Sauvy on model of the third estate (Fr. tiers état) of Revolutionary France; his first world (The West) and second world (the Soviet bloc) never caught on.

thirst (n.) --- O.E. þurst, from W.Gmc. *thurstus (cf. O.S. thurst, Fris. torst, Du. dorst, O.H.G., Ger. durst), from P.Gmc. *thurs-, from PIE base *ters- "dry" (see terrain). Fig. sense of "vehement desire" is attested from c.1200. The verb is O.E. þyrstan; the fig. sense of the verb was present in O.E. Thirsty is O.E. þurstig.

thirteen --- c.1430, metathesis of O.E. þreotene (Mercian), þreotiene (W.Saxon), from þreo "three" + -tene (see -teen). Cf. O.Fris. thretten, Du. dertien, Ger. dreizehn. Not an unlucky number in medieval England, but associated rather with the customary "extra item" (e.g. baker's dozen). Superstitions began with association with the Last Supper, and the unluckiness of 13 sitting down together to dine (attested from 1695). Most of the modern superstitions (buildings with floor "12-A," etc.) have developed since 1890.

thirty --- c.1413, metathesis of O.E. þritig, from þri, þreo "three" + -tig "group of ten" (see -ty (1)). Cf. O.Fris. thritich, O.S. thritig, Du. dertig, O.H.G. drizzug, Ger. dreissig. Thirty Years' War (1842) was a religious power struggle waged 1618-48, mainly on Ger. soil. The symbol -30- as printer and telegrapher's code to indicate the last sheet or line of copy or a dispatch is recorded from 1895. In 20c. jargon of journalism, it came to be a traditional sign-off signal and slang word for "the end."

this --- O.E. þis, neuter demonstrative pronoun and adj. (masc. þes, fem. þeos), probably from a North Sea Gmc. pronoun formed by combining the base *þa- (see that) with -s, which is probably identical with O.E. se "the" (representing here "a specific thing"), but it may be O.E. seo, imperative of see (v.) "to behold." Cf. O.S. these, O.N. þessi, Du. deze, O.Fris. this, O.H.G. deser, Ger. dieser. Once fully inflected, with 10 distinct forms (see table below); the oblique cases and other genders gradually fell away by 15c. The O.E. plural was þæs (nom. and acc.), which in Northern M.E. became thas, and in Midlands and Southern England became thos. The Southern form began to be used late 13c. as the plural of that (replacing M.E. tho, from O.E. þa) and acquired an -e (apparently from the influence of M.E. adj. plurals in -e; cf. alle from all, summe from sum "some"), emerging early 14c. as modern those. About 1175 thes (probably a variant of O.E. þæs) began to be used as the plural of this, and by 1200 it had taken the form these, the final -e acquired via the same mechanism that gave one to those.

thistle --- prickly herbaceous plant, O.E. þistel, from P.Gmc. *thikhstula (cf. O.H.G. distil, Ger. Distel, O.N. þistell, Dan. tidsel), of unknown origin. Emblem of Scotland since 15c.

thither --- O.E. þider "to or toward that place," altered (by infl. of its opposite hider) of earlier þæder "to that place," from P.Gmc. *thadra- (cf. O.N. þaðra "there"), from *tha (see that) + PIE suffix denoting motion toward (cf. Goth. -dre, Skt. -tra). The medial -th- developed in M.E. but was rare before 1525 (cf. gather, murder, burden).

thole (n.) --- peg, from O.E. þoll, from P.Gmc. *thulnaz (cf. O.N. þollr, M.L.G. dolle, E.Fris. dolle, Du. dol), of unknown origin. No record of the word in Eng. from c.1000 to c.1440.

thole (v.) --- to be subjected to or exposed to, to endure without complaint, now Scottish and Northern Eng. dial., from O.E. þolian, from P.Gmc. stem *thul- (cf. O.S. tholon, O.H.G. dolon, Ger. geduld, O.N. þola, Goth. þulan), cognate with L. tolerare (see toleration).

Thomas --- from Gk. Thomas, of Aramaic origin and said to mean "a twin" (John's gospel refers to Thomas as ho legomenos didymos "called the twin;" cf. Syriac toma "twin," Arabic tau'am "twin"). Before the Conquest, found only as the name of a priest. After 1066, one of the most common given names. Doubting Thomas is from John xx:25; A Thomist (1533, from M.L. Thomista, 1359) is a follower of 13c. scholastic theologian St. Thomas Aquinas. (Also see Tom, Tommy).

Thompson --- type of sub-machine gun, 1919, named for U.S. Gen. John T. Thompson (1860-1940), who conceived it and whose company financed it.

thong --- O.E. þwong "thong, narrow strip of leather (used as a cord, band, strip, etc.)," from P.Gmc. *thwangaz (cf. O.N. þvengr), from PIE base *twengh- "to press in on, to restrain." As a kind of sandal, first attested 1965; as a kind of bikini briefs, 1990.

Thor --- Odin's eldest son, strongest of the gods though not the wisest, c.1020, from O.N. Þorr, lit. "thunder," from *þunroz, related to O.E. þunor (see thunder).

thorax --- chest, c.1400, from L. thorax, from Gk. thorax (gen. thorakos) "breastplate, chest," of unknown origin.

Thorazine --- central nervous system depressant, 1954, proprietary name (Smith, Kline & French) formed from a rearrangement of various elements in the full chemical name.

thorium --- rare metallic element, 1832, from Mod.L., named 1828-9 by its discoverer, Swed. chemist Jöns Jakob Berzelius (1779-1848) in honor of the Scand. god Thor (q.v.).

thorn --- O.E. þorn "sharp point on a stem or branch," earlier "thorny tree or plant," from P.Gmc. *thurnuz (cf. O.S. thorn, Du. doorn, O.H.G. dorn, Ger. Dorn, O.N. þorn, Goth. þaurnus), from PIE *trnus (cf. O.C.S. trunu "thorn," Skt. trnam "blade of grass," Gk. ternax "stalk of the cactus," Ir. trainin "blade of grass"), from *(s)ter-n- "thorny plant," from base *ster- "stiff." Fig. sense of "anything which causes pain" is recorded from c.1230 (thorn in the flesh is from II Cor. xii.7). Also an O.E. and Icelandic runic letter (þ), named for the word of which it was the initial. Thorny is O.E. þornig; fig. sense is attested from c.1340.

thorough --- c.1489, adj. use of O.E. þuruh (adv.) "from end to end, from side to side," stressed variant of þurh (adv., prep.), see through. Thoroughfare is recorded from c.1386, "passage or way through."

thoroughbred (adj.) --- 1701, of persons, "thoroughly accomplished," from thorough + past tense of breed. In the horse sense of "of pure breed or stock" it dates from 1796; the noun is first recorded 1842.

thorp --- O.E. ðorp "village, hamlet, farm, estate," reinforced by O.N. ðorp, both from P.Gmc. *thurpa- (cf. O.Fris. thorp, Fris. terp, M.Du., Du. dorp, Ger. dorf "village," Goth. þaurp "estate, land, field"), probably from PIE base *treb- "dwelling." Preserved in place names ending in -thorp, -thrup.

those --- Midlands and southern variant of O.E. þas, nominative and accusative plural of þes, þeos "this" (see this).

Thoth --- ancient Egyptian god of wisdom and magic, from L., from Gk. Thoth, from Egyptian Tehuti.

thou --- 2nd nominative singular personal pronoun, O.E. þu, from P.Gmc. *thu (cf. O.Fris. thu, M.Du., M.L.G. du, O.H.G., Ger. du, O.N. þu, Goth. þu), from PIE *tu-, second person singular pronoun (cf. L. tu, Ir. tu, Welsh ti, Gk. su, Lith. tu, O.C.S. ty, Skt. twa-m). Superseded in M.E. by plural form you (from a different root), but retained in certain dialects (e.g. Philadelphia Quakers). The plural at first was used in addressing superior individuals, later also (to err on the side of propriety) strangers, and ultimately all equals. By c.1450 the use of thou to address inferiors gave it a tinge of insult unless addressed by parents to children, or intimates to one another. Hence the verb meaning "to use 'thou' to a person" (c.1440).

though --- c.1200, from O.E. þeah, and in part from O.N. þo "though," both from P.Gmc. *thaukh (cf. Goth. þauh, O.Fris. thach, M.Du., Du. doch, O.H.G. doh, Ger. doch), from PIE demonstrative pronoun *to- (see that). The evolution of the terminal sound did not follow laugh, tough, etc., though a tendency to end the word in "f" existed c.1300-1750 and persists in dialects.

thought (n.) --- O.E. þoht, geþoht, from stem of þencan "to conceive of in the mind, consider" (see think). Cognate with the second element in Ger. Gedächtnis "memory," Andacht "attention, devotion," Bedacht "consideration, deliberation." Thoughtful "given to thinking, meditative" is attested from c.1200; sense of "considerate of others" is first recorded 1851 (thoughtless "inconsiderate" is attested from 1794). Second thought "later consideration" is recorded from 1642. Thought-crime is from "Nineteen Eighty-Four" (1949); thought police is attested from 1946, originally in ref. to pre-war Japanese Special Higher Police (Tokubetsu Koto Keisatsu).

thousand --- O.E. þusend, from P.Gmc. *thusundi (cf. O.Fris. thusend, Du. duizend, O.H.G. dusunt, Ger. tausend, O.N. þusund, Goth. þusundi); related to words in Balto-Slavic (cf. Lith. tukstantis, O.C.S. tysashta, Pol. tysiac, Czech tisic), and probably ultimately a compound with indefinite meaning "several hundred" or "a great multitude" (with first element perhaps related to Skt. tawas "strong, force"). Used to translate Gk. khilias, L. mille, hence the refinement into the precise modern meaning. There was no general IE word for "thousand." Slang shortening thou first recorded 1867. Thousand island dressing (1916) is presumably named for the region of New York on the St. Lawrence River.

thrall --- O.E. þræl "bondsman, serf, slave," from O.N. þræll "slave, servant," probably from P.Gmc. *thrakhilaz, lit. "runner," from root *threh- "to run" (cf. O.H.G. dregil "servant," prop. "runner;" O.E. þrægan, Goth. þragjan "to run").

thrash --- 1588, "to separate grains from wheat, etc., by beating," dial. variant of threshen (see thresh). Sense of "beat (someone) with (or as if with) a flail" is first recorded 1606. Meaning "to make wild movements like those of a flail or whip" is attested from 1846. Type of fast heavy metal music first called by this name 1982.

thread (n.) --- O.E. þræd "fine cord, especially when twisted" (related to þrawan "to twist"), from P.Gmc. *thrædus (cf. M.Du. draet, Du. draad, O.H.G. drat, Ger. Draht, O.N. þraðr), from suffixed form of base *thræ- "twist" (see throw). Meaning "spiral ridge of a screw" is from 1674. The verb meaning "to put thread through a needle" is recorded from c.1366; in ref. to film cameras from 1913. The dancing move called thread the needle is attested from 1844. Threads, slang for "clothes" is 1926, Amer.Eng. Threadbare is recorded from 1362, from the notion of "having the nap worn off," leaving bare the threads.

threat --- O.E. þreat "crowd, troop," also "oppression, menace," related to þreotan "to trouble, weary," from P.Gmc. *threutanan (cf. Ger. verdrießen "to vex"), from PIE *trud- "push, press" (cf. L. trudere "to press, thrust," O.C.S. trudu "oppression," M.Ir. trott "quarrel, conflict," M.Welsh cythrud "torture, torment, afflict"). Sense of "conditional declaration of hostile intention" was in O.E. The verb threaten is O.E. þreatnian; threatening in the sense of "portending no good" is recorded from 1530.

three --- O.E. þreo, fem. and neut. (masc. þri, þrie), from P.Gmc. *thrijiz (cf. O.Fris. thre, M.Du., Du. drie, O.H.G. dri, Ger. drei, O.N. þrir, Dan. tre), from PIE *trejes (cf. Skt. trayas, Avestan thri, Gk. treis, L. tres, Lith. trys, O.C.S. trye, Ir., Welsh tri "three"). 3-D first attested 1952, abbreviation of three-dimensional (1878). Three-piece suit is recorded from 1909. Three cheers for ______ is recorded from 1751. Three-martini lunch is attested from 1972. Three-ring circus first recorded 1898. Three-sixty "complete turnaround" is from 1927, originally among aviators, in ref. to the number of degrees in a full circle. Three musketeers translates Fr. les trois mousquetaires, title of an 1844 novel by Alexandre Dumas père.

threnody --- song of lamentation, 1634, from Gk. threnodia, from threnos "dirge, lament," + oide "ode." Gk. threnos probably is from a PIE imitative base meaning "to murmur, hum;" cf. O.E. dran "drone," Goth. drunjus "sound," Gk. tenthrene "a kind of wasp."

thresh --- O.E. þrescan, þerscan "to beat, sift grain by trampling or beating," from P.Gmc. *threskanan "to thresh," originally "to tread, to stamp noisily" (cf. M.Du. derschen, Du. dorschen, O.H.G. dreskan, Ger. dreschen, O.N. þreskja, Goth. þriskan), from PIE base *tere- "to rub, turn" (see throw). The basic notion is of treading out wheat under foot of men or oxen, later, with the advent of the flail, the word acquired its modern extended sense of "to knock, beat, strike." The original Gmc. sense is suggested by the use of the word in Romanic languages that borrowed it, e.g. It. trescare "to prance," O.Fr. treschier "to dance," Sp. triscar "to stamp the feet." The thresher shark (1609) so called for its long upper tail shape.

threshold --- O.E. þrescold, þærscwold, þerxold "doorsill, point of entering," first element related to O.E. þrescan (see thresh), with its original sense of "tread, trample." Second element of unknown origin and much transformed in all the Gmc. languages; in Eng. it probably has been altered to conform to hold, but the oft-repeated story that the threshold was a barrier placed at the doorway to hold the chaff flooring in the room is mere folk etymology. Cognates include O.N. þreskjoldr, Swed. tröskel, O.H.G. driscufli, Ger. dial. drischaufel.

thrice --- c.1200, from O.E. þriga, þriwa "thrice" (from þrie "three;" see three) + adverbial genitive -es, changed to -ce c.1600 to reflect voiceless pronunciation.

thrift --- c.1305, "fact or condition of thriving," also "prosperity, savings" (1310), from M.E. thriven "to thrive" (see thrive), possibly infl. by O.N. þrift, variant of þrif "prosperity," from þrifask "to thrive." Sense of "habit of saving, economy" first recorded 1553 (thrifty in this sense is recorded from 1526; also see spendthrift). Thrift shop first attested 1947.

thrill (v.) --- c.1300, "to pierce, penetrate," metathesis of O.E. þyrlian, from þyrel "hole" (in M.E., also "nostril"), from þurh "through" (cf. M.H.G. dürchel "pierced, perforated") + -el. Meaning "give a shivering, exciting feeling" is first recorded 1592, via metaphoric notion of "pierce with emotion." The noun in this sense is from 1680; meaning "a thrilling experience" is attested from 1936. Thriller "sensational story" is from 1889.

thrive --- c.1200, from O.N. þrifask "to thrive," originally "grasp to oneself," probably from O.N. þrifa "to clutch, grasp, grip" (cf. Swed. trifvas, Dan. trives "to thrive, flourish"), of unknown origin.

throat --- O.E. þrote (implied in þrotbolla "the Adam's apple, larynx," lit. "throat boll"), related to þrutian "to swell," from P.Gmc. *thrut- (cf. O.H.G. drozza, Ger. Drossel, O.S. strota, M.Du. strote, Du. strot "throat"), perhaps from PIE *trud- (cf. O.E. þrutian "to swell," O.N. þrutna "to swell"). The notion is of "the swollen part" of the neck. It. strozza "throat," strozzare "to strangle" are Gmc. loan-words. College slang for "competitive student" is 1970s, from cutthroat.

throb (v.) --- 1362 (implied in throbbing), of uncertain origin, perhaps meant to represent in sound the pulsation of arteries and veins or the heart. The noun is first attested 1579.

throe --- c.1200, throwe "pain, pang of childbirth, agony of death," possibly from O.E. þrawan "twist, turn, writhe" (see throw), or altered from O.E. þrea (gen. þrawe) "affliction, pang, evil, threat" (related to þrowian "to suffer"), from P.Gmc. *thrawo (cf. M.H.G. dro "threat," Ger. drohen "to threaten"). Modern spelling first recorded 1615.

thrombosis --- 1706, Mod.L., from Gk. thrombosis "a clumping or curdling" (from thrombousthai "become curdled or clotted," from thrombos "clot, curd, lump") + -osis.

throne --- c.1240, from O.Fr. trone (12c.), from L. thronus, from Gk. thronos "elevated seat, chair, throne," from PIE base *dher- "to hold firmly, support" (cf. L. firmus "firm, steadfast, strong, stable," Skt. dharma "statute, law;" see firm (adj.)). Colloquial meaning "toilet" is recorded from 1922.

throng (n.) --- c.1300, probably shortened from O.E. geþrang "crowd, tumult" (related to verb þringan "to push, crowd, press"), from P.Gmc. *thrangan (cf. O.N. þröng, Du. drang, Ger. Drang "crowd, throng"). The verb, in the sense of "go in a crowd," is first recorded 1534.

throstle --- thrush, O.E. þrostle, from P.Gmc. *thrustalo (cf. O.S. throsla, O.H.G. droscala, Ger. Drossel "thrush"), altered from (perhaps a dim. of) *thurstaz (see thrush), though OED considers this a distinct word from the same PIE root.

throttle (v.) --- strangle to death, c.1400, probably from M.E. throte "throat" (see throat). The noun, in the mechanical sense, is first recorded 1870s, from throttle-valve (1824), but was used earlier as a synonym for "throat" (1547); it appears to be an independent formation, not derived from the verb.

through --- c.1300, metathesis of O.E. þurh, from W.Gmc. *thurkh (cf. O.S. thuru, O.Fris. thruch, M.Du. dore, Du. door, O.H.G. thuruh, Ger. durch, Goth. þairh "through"), from PIE base *tr- "through" (cf. Skt. tirah, Avestan taro "through, beyond," L. trans "beyond," O.Ir. tre, Welsh tra "through"). Not clearly differentiated from thorough until early Mod.Eng. Spelling thro was common 15c.-18c. Reformed spelling thru (1917) is mainly Amer.Eng.

throughout --- late O.E. þurhut; see through + out (cf. Ger. durchaus, 16c.).

throughway --- expressway, large toll road, 1934, Amer.Eng., from through + way.

throw (n.) --- act of throwing, 1530, from throw (v.). Wrestling sense is first attested 1819.

throw (v.) --- to project, propel, c.1300, from O.E. þrawan "to twist, turn writhe" (pt. þreow, pp. þrawen), from P.Gmc. *thræ- (cf. O.S. thraian, M.Du. dræyen, Du. draaien, O.H.G. draen, Ger. drehen "to turn, twist;" not found in Scand. or Gothic), from PIE *tere- "to rub, turn, rub by turning, bore" (cf. Skt. turah "wounded, hurt," Gk. teirein "to rub, rub away," L. terere "to rub, thresh, grind, wear away," O.C.S. tiro "to rub," Lith. trinu "to rub," O.Ir. tarathar "borer," Welsh taraw "to strike"). Not the usual O.E. word for "to throw" (weorpan, related to warp was common in this sense). The sense evolution may be via the notion of whirling a missile before throwing it. The sense of "put by force" (e.g. throw in jail) is first recorded 1560; that of "to confuse, flabbergast" is from 1844; that of "lose deliberately" is from 1868. To throw the book at (someone) is 1932, from notion of judge sentencing a criminal from a law book full of possible punishments. To throw (one's) hat in the ring "issue a challenge," esp. to announce one's candidacy, first recorded 1917. To throw up "vomit" is first recorded 1732.

throw away (v.) --- 1382, "to reject, cast from oneself," from throw (v.) + away. More literal meaning of "dispose of as useless, release from one's possession as unneeded" is first recorded 1530. Throw-away (adj.) is first recorded 1924, originally of prices so low they amounted to giving away the merchandise; with ref. to disposable goods, it is attested from 1969.

throwback --- revision to an ancestral type or character, 1888, from throw (v.) + back (adv.); earlier it meant "a reverse in a course or progress, a relapse" (1856).

thrum (v.) --- play a stringed instrument, 1592, from the noun (1553), of imitative origin.

thrush (1) --- type of songbird, O.E. þyrsce (related to throstle), from P.Gmc. *thruskjon (cf. O.N. þröstr, Norw. trost, O.H.G. drosca), from PIE *trozdo- (cf. L. turdus, Lith. strazdas "thrush," M.Ir. truid, Welsh drudwy "starling," O.C.S. drozgu, Rus. drozdu).

thrush (2) --- throat disease, 1665, probably from a Scand. source (cf. Norw., Dan. trøske, Swed. torsk), but its roots and original meaning are unclear.

thrust (v.) --- c.1175, from O.N. þrysta "to thrust, force," from P.Gmc. *thrustijanan, perhaps from PIE *trud- "push, press" (see threat), but OED finds this derivation doubtful. The noun is recorded from 1513; fig. sense of "principal theme, aim, point, purpose" is recorded from 1968.

thud (v.) --- O.E. þyddan "to strike, thrust," of imitative origin. Sense of "hit with a dull sound" first recorded 1796. The noun is attested from 1513.

thug --- 1810, "member of a gang of murderers and robbers in India who strangled their victims," from Marathi thag, thak "cheat, swindler," Hindi thag, perhaps from Skt. sthaga-s "cunning, fraudulent," possibly from sthagayati "(he) covers, conceals," from PIE base *(s)teg- "cover" (see stegosaurus). Transferred sense of "ruffian, cutthroat" first recorded 1839. The more correct Indian name is phanseegur, and the activity was described in Eng. as far back as c.1665. Rigorously prosecuted by the British from 1831, they were driven from existence, but the process extended over the rest of the 19c.