Online Etymology Dictionary

turban (n.): 1560s, from Middle French turbant (15c.), from Italian turbante (Old Italian tolipante), from Turkish tülbent "gauze, muslin, tulle," from Persian dulband "turban." The change of -l- to -r- may have taken place in Portuguese India and thence been picked up in other European languages. A men's headdress in Muslim lands, it was popular in Europe and America c. 1776-1800 as a ladies' fashion. Related: Turbaned.
turbid (adj.): 1620s, from Latin turbidus "muddy, full of confusion," from turbare "to confuse, bewilder," from turba "turmoil, crowd," probably from Greek tyrbe "turmoil, tumult, disorder," from PIE *(s)twer- (1) "to turn, whirl" (see storm (n.)). Related: Turbidly; turbidness.
turbidity (n.): 1782, from Medieval Latin turbiditas, from Latin turbidus (see turbid). Turbidity current is from 1939.
turbine (n.): 1838, from French turbine (19c.), from Latin turbinem (nominative turbo) "spinning top, eddy, whirlwind, that which whirls," 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.
turbo-: word-forming element, abstracted c. 1900 from turbine; influenced by Latin turbo "spinning top." E.g. turbocharger (1934), aeronautic turboprop (1945, with second element short for propeller); turbojet (1945).
turbot (n.): large, edible flatfish, c. 1300, from Old French turbut (12c., Modern French turbot), probably from a Scandinavian source (compare 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.): early 15c., from Late Latin turbulentia "trouble, disquiet," from Latin turbulentus (see turbulent). In reference to atmospheric eddies that affect airplanes, by 1918. Related: Turbulency.
turbulent (adj.): early 15c., "disorderly, tumultuous, unruly" (of persons), from Middle French turbulent (12c.), from Latin turbulentus "full of commotion, restless, disturbed, boisterous, stormy," figuratively "troubled, confused," from turba "turmoil, crowd" (see turbid). In reference to weather, from 1570s. Related: Turbulently.
turd (n.): Old English tord "piece of excrement," from Proto-Germanic *turdam (source also of Middle Dutch torde "piece of excrement," Old Norse tord-yfill, Dutch tort-wevel "dung beetle"), from PIE *drtom, past participle of root *der- (2) "to split, peel, flay, tear;" thus "that which is separated ("torn off") from the body" (compare shit (v.) from root meaning "to split;" Greek skatos from root meaning "to cut off; see scatology). As a type of something worthless and vile, it is attested from mid-13c. Meaning "despicable person" is recorded from mid-15c.
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 dung, that I may win Christ"]
tureen (n.): 1706, from French terrine "earthen vessel," from Old French therine (15c.), noun use of fem. of terrin (adj.) "earthen," from Gallo-Roman *terrinus, from Latin terrenus "of the earth" (see terrain).
turf (n.): Old English turf, tyrf "slab of soil and grass, sod," also "surface of grassland," from Proto-Germanic *turb- (source also of Old Norse torf, Danish tørv, Old Frisian turf, Old High German zurba, German Torf), from PIE root *drebh- "to wind, compress" (source also of Sanskrit darbhah "tuft of grass").

Especially "the race course," hence the turf "the profession of racing horses" (1755). French tourbe "turf" is a Germanic loan-word. The Old English plural was identical with the singular, 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, distended," from turgere "to swell," of unknown origin. Figurative use in reference to prose is from 1725. Related: Turgidly; turgidness.
turgor (n.): 1857, from medical Latin turgor, from Latin turgere "to swell" (see turgid).
Turin: city in northern Italy, Italian Torino, Roman Augusta Taurinorum, probably from the Taurini, a Ligurian people who had a capital there, the name perhaps from Celtic *tauro "mountain" or *tur "water," but long interpreted by folk etymology as from Latin taurus "bull."
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. Compare Chinese tu-kin, recorded from c. 177 B.C.E. as the name 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."

In English, the Ottoman sultan was the Grand Turk (late 15c.), and the Turk was used collectively for the Turkish people or for Ottoman power (late 15c.). From 14c. and especially 16c.-18c. Turk could mean "a Muslim," reflecting the Turkish political power's status in the Western mind as the Muslim nation par excellence. Hence Turkery "Islam" (1580s); turn Turk "convert to Islam."

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, originally "guinea fowl" (Numida meleagris), a bird imported from Madagascar via Turkey, and called guinea fowl when brought by Portuguese traders from West Africa. The larger North American bird (Meleagris gallopavo) was domesticated by the Aztecs, introduced to Spain by conquistadors (1523) and thence to wider Europe. The word turkey first was applied to it in English 1550s because it was identified with or treated as a species of the guinea fowl, and/or because it got to the rest of Europe from Spain by way of North Africa, then under Ottoman (Turkish) rule. Indian corn was originally turkey corn or turkey wheat in English for the same reason.

The Turkish name for it is hindi, literally "Indian," probably influenced by Middle French dinde (c. 1600, contracted from poulet d'inde, literally "chicken from India," Modern French dindon), based on the then-common misconception that the New World was eastern Asia.
After the two birds were distinguished and the names differentiated, turkey was erroneously retained for the American bird, instead of the African. From the same imperfect knowledge and confusion Melagris, the ancient name of the African fowl, was unfortunately adopted by Linnæus as the generic name of the American bird. [OED]
The New World bird itself reputedly reached England by 1524 at the earliest estimate, though a date in the 1530s seems more likely. The wild turkey, the North American form of the bird, was so called from 1610s. 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. To talk turkey (1824) supposedly comes from an old tale of a Yankee attempting to swindle an Indian in dividing up a turkey and a buzzard as food.
Turkey: country name, late 14c., from Medieval Latin Turchia, from Turcus (see Turk) + -ia.
turkey-vulture (n.): 1823, from turkey + vulture. From 1670s as turkey-buzzard.
Turkish (adj.): 1540s, from Turk (n.) + -ish. As a noun, "the Turkish language," from 1718.
Turkoman: also Turcoman, 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, altered 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. Klein suggests it might be a folk-etymology corruption of Arabic kurkum "curcuma, saffron."
turmoil (n.): 1520s, of uncertain origin, 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 away or around; draw aside, cause to turn; change, transform; turn on a lathe" (Modern French tourner), both from Latin tornare "to polish, round off, fashion, turn on a lathe," from tornus "lathe," from Greek tornos "lathe, tool for drawing circles," from PIE root *tere- (1) "to rub, rub by turning, turn, twist" (see throw (v.)). Transitive sense in English is from c. 1300. Related: Turned; turning.

Use in expression to turn (something) into (something else) probably retains the classical sense of "to shape on a lathe." To turn up "arrive, make an appearance" is recorded from 1755. Turn about "by turns, alternately" is recorded from 1640s. 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 1640s in a figurative sense "point at which a decisive change takes place;" literal sense "point on which a thing turns; point at which motion in one direction ceases and that in another or contrary direction begins" is from 1660s.
turn (n.): c. 1200, "action of rotating," from Anglo-French tourn (Old French torn, tour), from Latin tornus "turning lathe;" also partly 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 (as in 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. The automatic automobile turn-signal is from 1915. Turn-sick "dizzy," is attested from early 15c. 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.
turn-around (n.): also turnaround, 1936, from verbal phrase turn around "reverse," 1880, American English, from turn (v.) + around (adv.).
turn-off (n.): "something that dampens one's spirits" recorded by 1971 (said to have been in use since 1968), from verbal phrase turn off "stop the flow of" (1850), from turn (v.) + off (adv.). Turn-off (n.) as "place where one road diverges from another" is from 1881.
turn-on (n.): that which arouses or excites, 1968, originally of psychedelic drugs, from verbal phrase turn on "activate (a mechanism)" (1833), specifically from figurative sense turn (someone) on "excite, stimulate, arouse," recorded from 1903; from turn (v.) + on (adv.).
turn-out (n.): "audience, assemblage of persons who have come to see a show, spectacle, etc.," 1816, from the verbal phrase; see turn (v.) + out (adv.).
turnbuckle (n.): also turn-buckle, 1703, "catch or fastening for windows and shutters," from turn (v.) + buckle (n.). Meaning "coupling with internal screw threads for connecting metal rods" is attested from 1877.
turncoat (n.): 1550s, from turn (v.) + coat (n.). The image is of one who attempts 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, "one who works a lathe," agent noun from turn (v.). As a surname from late 12c.
turnip (n.): c. 1500, 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 only once, it is recorded from 1934. The notion probably is of something that can be accomplished with a single turn of a key.
turnover (n.): also turn-over, 1650s, "action of turning over," from the verbal phrase; see turn (v.) + over (adv.). As a kind of pastry tart, 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 (v.) + stile (n.).
turntable (n.): also turn-table, "circular platform designed to turn upon its center," 1835, originally in the railroad sense, from turn (v.) + table (n.). The record-player sense is attested from 1908.
turpentine (n.): early 14c., "semi-liquid resin of the terebinth tree," terbentyn, from Old French terebinte "turpentine" (13c.), from Latin terebintha resina "resin of the terebinth tree," from Greek rhetine terebinthe, from fem. of terebinthos (see terebinth). 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, physically ugly, base, unsightly," figuratively "morally ugly, scandalous, shameful," of unknown origin. Klein suggests perhaps originally "what one turns away from" (compare Latin trepit "he turns").
turquoise (n.): greenish-blue precious stone, 1560s, from Middle French, replacing 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. Cognate with Spanish turquesa, Medieval Latin (lapis) turchesius, Middle Dutch turcoys, German türkis, Swedish turkos. As an adjective, 1570s. As a color name, attested from 1853. "Chemically it is a hydrated phosphate of aluminum and copper" [Flood].
turret (n.): c. 1300, touret "small tower forming part of a city wall or castle," from Old French torete (12c., Modern French tourette), diminutive of tour "tower," from Latin turris (see tower (n.1)). Meaning "low, flat gun-tower on a warship" is recorded from 1862, later also of tanks. Related: Turreted. Welsh twrd is from English.
turtle (n.1): "tortoise," c. 1600, originally "marine tortoise," from French tortue, tortre (13c.) "turtle, tortoise" (often associated with diabolical beasts), of unknown origin. The English word perhaps is a sailors' mauling of the French one, influenced by the similar sounding turtle (n.2). Later extended to land tortoises; sea-turtle is attested from 1610s.
turtle (n.2): "turtledove," Old English turtle, dissimilation of Latin turtur "turtledove," a reduplicated form imitative of the bird's coo. Graceful, harmonious and affectionate to its mate, hence a term of endearment in Middle English. Turtle-dove is attested from c. 1300.
turtleneck (n.): also turtle-neck "close-fitting collar," 1893, from turtle (n.1) + neck (n.).
Tuscaloosa: river in Alabama, first attested in Spanish as Tascaluza, from Choctaw (Muskogean) taska-losa, literally "warrior-black."
Tuscan (n.): late 14c., from Italian Toscano, from Late Latin Tuscanus "belonging to the Tusci," a people of ancient Italy, from Tuscus, earlier *Truscus, shortened form of Etruscus (see Etruscan).
Tuscarora: Iroquoian people originally inhabiting what is now North Carolina, 1640s, from Catawba (Siouan) /taskarude:/, literally "dry-salt eater," a folk-etymologizing of the people's name for themselves, Tuscarora (Iroquoian) /skaru:re/, literally "hemp-gatherers."