Online Etymology Dictionary

turbine (n.): 1838, from French turbine, from Latin turbinem (nominative turbo) "spinning top, eddy, whirlwind," related to turba "turmoil, crowd" (see turbid). Originally applied to a wheel spinning on a vertical axis, driven by falling water. Turbo in reference to gas turbine engines is attested from 1904. Turbocharger is from 1934. Aeronautic turboprop is attested from 1945, with second element short for propeller.
turbo-: word-forming element, abstracted c.1900 from turbine; influenced by Latin turbo "spinning top."
turbot (n.): "large flat fish," c.1300, from Old French turbut (12c.), probably from a Scandinavian source (cf. Old Swedish törnbut, from törn "thorn" + but "flatfish;" see halibut). But OED says of uncertain origin and speculates on a connection to Latin turbo "spinning top."
turbulence (n.): 1590s; see turbulent + -ence.
turbulent (adj.): 1530s, "disorderly, tumultuous, unruly" (of persons), from Middle French turbulent (12c.), from Latin turbulentus "full of commotion, restless," from turba "turmoil, crowd" (see turbid). In reference to weather, attested from 1570s.
turd (n.): Old English tord, from Proto-Germanic *turdam (cf. Middle Dutch torde "piece of excrement," Old Norse tord-yfill, Dutch tort-wevel "dung beetle"), from PIE *drtom, past participle of root *d(e)r- "flay, tear," thus "that which is separated (or torn off) from the body" (cf. shit from root meaning "to split"). As a type of something worthless and vile, it is attested from mid-13c.
A tord ne yeue ic for eu alle ["The Owl and the Nightingale," c.1250]

Alle thingis ... I deme as toordis, that I wynne Crist. [Wyclif, Phil. iii.8, 1382; KJV has "I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord"]
Meaning "despicable person" is recorded from mid-15c.
tureen (n.): 1706, from French terrine "earthen vessel," from Old French therine (early 15c.), from terrin (adj.) "earthen," from Gallo-Romance *terrinus, from Latin terrenus "of the earth" (see terrain).
turf (n.): Old English turf, tyrf "slab of soil and grass," also "surface of grassland," from Proto-Germanic *turb- (cf. Old Norse torf, Danish tørv, Old Frisian turf, Old High German zurba, German Torf), from PIE root *drbh- (cf. Sanskrit darbhah "tuft of grass").

French tourbe "turf" is a Germanic loan-word. The Old English plural was identical with the singluar, but in Middle English turves sometimes was used. Slang meaning "territory claimed by a gang" is attested from 1953 in Brooklyn, N.Y.; earlier it had a jive talk sense of "the street, the sidewalk" (1930s), which is attested in hobo use from 1899, and before that "the work and venue of a prostitute" (1860). Turf war is recorded from 1962.
turf (v.): early 15c., "to cover (ground) with turf," from turf (n.). Related: Turfed; turfing.
turgid (adj.): 1610s, from Latin turgidus "swollen, inflated," from turgere "to swell," of unknown origin. Figurative use in reference to prose is from 1725. Related: Turgidly; turgidness.
turgor (n.): 1876, from Late Latin turgor, from turgere "to swell" (see turgid).
Turing machine (n.): 1937, named for English mathematician and computer pioneer Alan M. Turing (1912-1954), who described such a device in 1936.
Turk (n.): c.1300, from French Turc, from Medieval Latin Turcus, from Byzantine Greek Tourkos, Persian turk, a national name, of unknown origin. Said to mean "strength" in Turkish. Cf. Chinese tu-kin, name given c.177 B.C.E. as that of a people living south of the Altai Mountains (identified by some with the Huns). In Persian, turk, in addition to the national name, also could mean "a beautiful youth," "a barbarian," "a robber."

Meaning "person of Irish descent" is first recorded 1914 in U.S., apparently originating among Irish-Americans; of unknown origin (Irish torc "boar, hog" has been suggested). Young Turk (1908) was a member of an early 20c. political group in the Ottoman Empire that sought rejuvenation of the Turkish nation. Turkish bath is attested from 1640s; Turkish delight from 1877.
turkey (n.): 1540s, "guinea fowl" (Numida meleagris), imported from Madagascar via Turkey, by Near East traders known as turkey merchants. The larger North American bird (Meleagris gallopavo) was domesticated by the Aztecs, introduced to Spain by conquistadors (1523) and thence to wider Europe, by way of North Africa (then under Ottoman rule) and Turkey (Indian corn was originally turkey corn or turkey wheat in English for the same reason).

The word turkey was first applied to it in English 1550s because it was identified with or treated as a species of the guinea fowl. The Turkish name for it is hindi, literally "Indian," probably via Middle French dinde (c.1600, contracted from poulet d'inde, literally "chicken from India," Modern French dindon), based on the common misconception that the New World was eastern Asia.

The New World bird itself reputedly reached England by 1524 at the earliest estimate, though a date in the 1530s seems more likely. By 1575, turkey was becoming the usual main course at an English Christmas. Meaning "inferior show, failure," is 1927 in show business slang, probably from the bird's reputation for stupidity. Meaning "stupid, ineffectual person" is recorded from 1951. Turkey shoot "something easy" is World War II-era, in reference to marksmanship contests where turkeys were tied behind a log with their heads showing as targets.
Turkey: country name, late 14c., from Medieval Latin Turchia, from Turcus (see Turk) + -ia.
Turkoman: c.1600, from Medieval Latin Turcomannus, from Persian Turkman, literally "Turk-like," from Turk + -man "like."
Turkophile: also Turcophile, 1876, from comb. form of Turk + -phile.
turmeric (n.): pungent powder made from the root of an East Indian plant, 1530s, from Middle English turmeryte (early 15c.), of uncertain origin, perhaps from Middle French terremérite "saffron," from Medieval Latin terra merita, literally "worthy earth," though the reason why it would be called this is obscure.
turmoil (n.): 1520s, perhaps an alteration of Middle French tremouille "mill hopper," in reference to the hopper's constant motion to and fro, from Latin trimodia "vessel containing three modii," from modius, a Roman dry measure, related to modus "measure." Attested earlier in English as a verb (1510s), though this now is obsolete.
turn (v.): late Old English turnian "to rotate, revolve," in part also from Old French torner "to turn," both from Latin tornare "turn on a lathe," from tornus "lathe," from Greek tornos "lathe, tool for drawing circles," from PIE root *tere- "to rub, rub by turning, turn, twist" (see throw). Expression to turn (something) into (something else) probably retains the classical sense of "to shape on a lathe" (attested in English from c.1300). Related: Turned; turning.

To turn up "arrive" is recorded from 1755. Turn-off "something that dampens one's spirits" recorded by 1971 (said to have been in use since 1968); to turn (someone) on "excite, stimulate, arouse" is recorded from 1903. Someone should revive turn-sick "dizzy," which is attested from mid-15c. To turn (something) loose "set free" is recorded from 1590s. Turn down (v.) "reject" first recorded 1891, American English. Turn in "go to bed" is attested from 1690s, originally nautical. To turn the stomach "nauseate" is recorded from 1620s. To turn up one's nose as an expression of contempt is attested from 1779. Turning point is attested by 1836 in a figurative sense; literal sense from 1856.
turn (n.): mid-13c., "action of rotation," from Anglo-French tourn (Old French tour), from Latin tornus "turning lathe;" also partly a noun of action from turn (v.). Meaning "an act of turning, a single revolution or part of a revolution" is attested from late 15c. Sense of "place of bending" (in a road, river, etc.) is recorded from early 15c. Meaning "beginning of a period of time" is attested from 1853 (e.g. turn-of-the-century, from 1921 as an adjectival phrase).

Sense of "act of good will" is recorded from c.1300. Meaning "spell of work" is from late 14c.; that of "an individual's time for action, when these go around in succession" is recorded from late 14c. Turn about "by turns, alternately" is recorded from 1640s. Phrase done to a turn (1780) suggests meat roasted on a spit. The turn of the screw (1796) is the additional twist to tighten its hold, sometimes with reference to torture by thumbscrews.
turnaround (n.): 1936, from verbal phrase turn around "reverse," 1880, American English.
turnbuckle (n.): 1703, "catch or fastening for windows and shutters," from turn + buckle (n.). Meaning "coupling with internal screw threads for connecting metal rods" is attested from 1877.
turncoat (n.): 1550s, from turn (v.) + coat (n.). Originally one who tried to hide the badge of his party or leader. The expression to turn one's coat "change principles or party" is recorded from 1560s.
turner (n.): c.1400, agent noun from turn (v.).
turnip (n.): 1530s, turnepe, probably from turn (from its shape, as though turned on a lathe) + Middle English nepe "turnip," from Old English næp, from Latin napus "turnip." The modern form of the word emerged late 18c.
turnkey (adj.): 1650s, "jailer," from turn (v.) + key (n.). In reference to a job that only has to be done once, it is recorded from 1934. The notion is of locking up afterward.
turnout (n.): "audience," 1816, from turn (v.) + out (adv.).
turnover (n.): 1650s, "action of turning over," from turn + over; meaning "kind of pastry tart" is attested from 1798. Meaning "number of employees leaving a place and being replaced" is recorded from 1955.
turnpike (n.): early 15c., "spiked road barrier used for defense," from turn + pike (n.2) "shaft." Sense transferred to "horizontal cross of timber, turning on a vertical pin" (1540s), which were used to bar horses from foot roads. This led to the sense of "barrier to stop passage until a toll is paid" (1670s). Meaning "road with a toll gate" is from 1748, shortening of turnpike road (1745).
turnstile (n.): 1640s, from turn + stile.
turntable (n.): 1835, originally in the railroad sense, from turn (v.) + table (n.). The record player sense is attested from 1908.
turpentine (n.): early 14c., terbentyn, from Old French terebinte, from Latin terebintha resina "resin of the terebinth tree," from Greek rhetine terebinthe, from fem. of terebinthos, earlier terminthos "terebinth tree," probably from a non-Indo-European language. By 16c. applied generally to resins from fir trees.
turpitude (n.): "depravity, infamy," late 15c., from Middle French turpitude (early 15c.), from Latin turpitudinem (nominative turpitudo) "baseness," from turpis "vile, ugly, base, shameful," used in both the moral and the physical senses; of unknown origin. Perhaps originally "what one turns away from" (cf. Latin trepit "he turns").
turquoise (n.): precious stone, 1560s, replacement from Middle French of Middle English turkeis, turtogis (late 14c.), from Old French fem. adjective turqueise "Turkish," in pierre turqueise "Turkish stone," so called because it was first brought to Europe from Turkestan or some other Turkish dominion (Sinai peninsula, according to one theory). Cognate with Spanish turquesa, Medieval Latin (lapis) turchesius, Middle Dutch turcoys, German türkis, Swedish turkos. As a color name, attested from 1853.
turret (n.): c.1300, "small tower," from Old French touret (12c.), diminutive of tour "tower," from Latin turris (see tower). Meaning "low, flat gun-tower on a warship" is recorded from 1862, later also of tanks. Related: Turreted.
turtle (n.1): reptile, c.1600, "marine tortoise," from French tortue "turtle, tortoise," of unknown origin. The English word is perhaps a sailors' mauling of the French one, influenced by the similar sounding turtle (n.2). Later extended to land tortoises. Turtleneck "close-fitting collar" is recorded from 1895.
turtle (n.2): "turtledove," Old English turtle, dissimilation of Latin turtur "turtledove," a reduplicated form imitative of the bird's call. Graceful, harmonious and affectionate to its mate, hence a term of endearment in Middle English. Turtledove is attested from c.1300.
Tuscan: late 14c., from Italian Toscano, from Late Latin Tuscanus "belonging to the Tusci," a race of ancient Italy, from Tuscus, earlier *Truscus, shortened form of Etruscus (cf. Etruscan).
Tuscarora: Iroquoian people, 1640s, from Iroquoian, literally "hemp-gatherers."
tush (n.): "backside, buttocks," 1962, an abbreviation of tochus (1914), from Yiddish tokhes, from Hebrew tahat "beneath."
tush (interj.): mid-15c.; see tut.
tushy (n.): also tushie, 1962, from tush (n.) + -y (3).
tusk (n.): Old English tux, tusc, cognate with Old Frisian tusk, probably from Proto-Germanic *tunthskaz (cf. Gothic tunþus "tooth"), extended form of the root of tooth. But there are no certain cognates outside Anglo-Frisian.
tussive (adj.): "pertaining to cough," 1857, from Latin tussis "cough," of unknown origin, + -ive.
tussle (v.): late 15c., Scottish and northern English variant of touselen (see tousle). Related: Tussled; tussling. The noun is first recorded 1620s but rare before 19c.
tussock (n.): 1540s, "tuft of hair," of uncertain origin; cf. earlier tusk (1520s) with the same meaning (and also of obscure origin). Meaning "tuft of grass" is first recorded c.1600.
tut: 1520s, along with tush (mid-15c.), a natural interjection expressing contempt.
tutee (n.): 1927; see tutor + -ee.
tutelage (n.): c.1600, from Latin tutela "a watching, protection," from variant past participle stem of tueri "watch over" (see tutor). Meaning "instruction, tuition" first appeared 1857.