trade-off (n.) Look up trade-off at Dictionary.com
also tradeoff, "sacrifice of one benefit for another," 1959, from verbal phrase to trade off; see trade (v.) + off (adv.).
trademark (n.) Look up trademark at Dictionary.com
also trade-mark, 1838 (the thing itself attested continuously from 14c., apparently originally the watermarks on paper), from trade (n.) + mark (n.1). Figurative use by 1869. As a verb, from 1904. Related: Trademarked; trademarking.
trader (n.) Look up trader at Dictionary.com
"dealer, trafficker, one engaged in commerce," 1580s, agent noun from trade (v.).
tradesman (n.) Look up tradesman at Dictionary.com
1590s, from genitive of trade (n.) + man (n.).
tradition (n.) Look up tradition at Dictionary.com
late 14c., "statement, belief, or practice handed down from generation to generation," especially "belief or practice based on Mosaic law," from Old French tradicion "transmission, presentation, handing over" (late 13c.) and directly from Latin traditionem (nominative traditio) "delivery, surrender, a handing down, a giving up," noun of action from past participle stem of tradere "deliver, hand over," from trans- "over" (see trans-) + dare "to give" (see date (n.1)). The word is a doublet of treason (q.v.). Meaning "a long-established custom" is from 1590s. The notion is of customs, ways, beliefs, doctrines, etc. "handed down" from one generation to the next.
"Nobody can make a tradition; it takes a century to make it." [Hawthorne, "Septimius Felton," 1872]
traditional (adj.) Look up traditional at Dictionary.com
1590s, "observing traditions;" c.1600, "handed down as tradition," from tradition + -al (1). In reference to jazz, from 1950. Related: Traditionally; traditionalist.
traduce (v.) Look up traduce at Dictionary.com
1530s, "alter, change over, transport," from Latin traducere "change over, convert," also "lead in parade, make a show of, dishonor, disgrace," originally "lead along or across, bring through, transfer" (source also of French traduire, Spanish traducir, Italian tradurre), from trans- "across" (see trans-) + ducere "to lead" (see duke (n.)). Sense of "defame, slander" in English is from 1580s, from Latin traducere in the sense of "scorn or disgrace," a figurative use from the notion of "to lead along as a spectacle." Related: Traduced; traducing.
traducer (n.) Look up traducer at Dictionary.com
1610s, agent noun from traduce (v.).
Trafalgar Look up Trafalgar at Dictionary.com
cape in southwestern Spain, from Arabic taraf-al-garb "end of the west," or taraf-agarr "end of the column" (in reference to the pillars of Hercules). The British naval victory over the French there was fought Oct. 21, 1805; hence London's Trafalgar Square, named in commemoration of it.
traffic (n.) Look up traffic at Dictionary.com
c.1500, "trade, commerce," from Middle French trafique (15c.), from Italian traffico (14c.), from trafficare "carry on trade," of uncertain origin, perhaps from a Vulgar Latin *transfricare "to rub across," from Latin trans- "across" (see trans-) + fricare "to rub" (see friction), with the original sense of the Italian verb being "touch repeatedly, handle."

Or the second element may be an unexplained alteration of Latin facere "to make, do." Klein suggests ultimate derivation of the Italian word from Arabic tafriq "distribution." Meaning "people and vehicles coming and going" first recorded 1825. Traffic jam is 1917, ousting earlier traffic block (1895). Traffic circle is from 1938.
traffic (v.) Look up traffic at Dictionary.com
1540s, "to buy and sell," from traffic (n.) and preserving the original commercial sense. Related: Trafficked; trafficking; trafficker. The -k- is inserted to preserve the "k" sound of -c- before a suffix beginning in -i-, -y-, or -e- (compare picnic/picnicking, panic/panicky, shellacshellacked).
tragedian (n.) Look up tragedian at Dictionary.com
"writer of tragedies," late 14c., from Old French tragediane (Modern French tragédien), from tragedie (see tragedy). Another word for this was tragician (mid-15c.). Meaning "actor in tragedies" is from 1590s. French-based fem. form tragedienne is from 1851. In late classical Greek, tragodos was the actor, tragodopoios the writer.
tragedy (n.) Look up tragedy at Dictionary.com
late 14c., "play or other serious literary work with an unhappy ending," from Old French tragedie (14c.), from Latin tragedia "a tragedy," from Greek tragodia "a dramatic poem or play in formal language and having an unhappy resolution," apparently literally "goat song," from tragos "goat" + oide "song" (see ode).

The connection may be via satyric drama, from which tragedy later developed, in which actors or singers were dressed in goatskins to represent satyrs. But many other theories have been made (including "singer who competes for a goat as a prize"), and even the "goat" connection is at times questioned. Meaning "any unhappy event, disaster" is from c.1500.
tragi-comedy (n.) Look up tragi-comedy at Dictionary.com
also tragicomedy, "characterized by both serious and comic scenes," 1570s, from Middle French tragicomédie (1540s), from Italian tragicommedia, from Late Latin tragicomoedia, contraction of tragicocomoedia (Plautus), from tragicus (see tragic) + comoedia (see comedy).
tragi-comic (adj.) Look up tragi-comic at Dictionary.com
"both serious and tragic," 1680s; see from tragi-comedy + -ic. Related: Tragi-comical (1560s).
tragic (adj.) Look up tragic at Dictionary.com
1540s, "calamitous, disastrous, fatal" ("resembling the actions in a stage tragedy"), shortened from tragical (late 15c.), modeled on Latin tragicus, from Greek tragikos "of or pertaining to tragedy; stately, majestic; plaintive," literally "goatish, of or pertaining to a goat," and perhaps referring to a satyr impersonated by a goat singer or satyric actor, from tragodia (see tragedy). Tragic flaw (1913) translates Greek hamartia. Related: Tragically.
tragus (n.) Look up tragus at Dictionary.com
"eminence at the opening of the ear," 1690s, Modern Latin, from Greek tragos in this sense (Rufus of Ephesus), properly "he-goat;" so called for the tuft of hair which grows there, which resembles a goat's beard.
trail (v.) Look up trail at Dictionary.com
c.1300, "to hang down loosely and flow behind" (of a gown, sleeve, etc.), from Old French trailler "to tow; pick up the scent of a quarry," ultimately from Vulgar Latin *tragulare "to drag," from Latin tragula "dragnet, javelin thrown by a strap," probably related to trahere "to pull" (see tract (n.1)). Transitive sense of "to tow or pull along the ground" is from c.1400. The meaning "follow the trail of" (an animal, etc.) is first recorded late 14c. Meaning "to lag behind" is from 1957. Related: Trailed; trailing.
trail (n.) Look up trail at Dictionary.com
early 14c., "trailing part of a robe, gown, etc.," from trail (v.). The meaning "track or smell left by a person or animal" is also from 1580s. Meaning "path or track worn in wilderness" is attested from 1807. Trail of Tears in reference to the U.S. government's brutally incompetent Cherokee removal of 1838-9 is attested by 1908.
trailblazer (n.) Look up trailblazer at Dictionary.com
by 1893, from trail (n.) + agent noun from blaze (v.3).
trailer (n.) Look up trailer at Dictionary.com
1580s, "hound or huntsman that follows a trail," agent noun from trail (v.). From 1610s as "Something that trails." From 1890 as "vehicle pulled by another;" originally a small carriage drawn along by a bicycle. Meaning "preview of a coming movie" first attested 1928. Trailer park "mobile home community" recorded by 1936. Trailer trash in use by 1986.
train (n.) Look up train at Dictionary.com
early 14c., "a drawing out, delay;" late 14c., "trailing part of a skirt, gown, or cloak;" also "retinue, procession," from Old French train "tracks, path, trail (of a rome or gown); act of dragging," from trainer "to pull, drag, draw," from Vulgar Latin *traginare, extended from *tragere "to pull," back-formation from tractus, past participle of Latin trahere "to pull, draw" (see tract (n.1)).,

General sense of "series, progression, succession, continuous course" is from late 15c. Train of thought first attested 1650s. The railroad sense "locomotive and the cars coupled to it" is recorded from 1820 (publication year, dated 1816), from notion of a "train" of wagons or carriages pulled by a mechanical engine.
train (v.) Look up train at Dictionary.com
"to discipline, teach, bring to a desired state by means of instruction," 1540s, probably from earlier sense of "draw out and manipulate in order to bring to a desired form" (late 14c.), specifically of the growth of branches, vines, etc. from mid-15c.; from train (n.). Sense of "point or aim" (a firearm, etc.) is from 1841. Sense of "fit oneself for a performance by a regimen or exercise" is from 1832. The meaning "to travel by railway" is recorded from 1856. Related: Trained; training.
train-spotting (n.) Look up train-spotting at Dictionary.com
1959 (train spotter attested from 1958), chiefly British English, in reference to the hobby of recording the numbers of railway locomotives one has observed; from train (n.) in the railroad sense + verbal noun from spot (v.).
trainable (adj.) Look up trainable at Dictionary.com
1540s, from train (v.) + -able.
trainee (n.) Look up trainee at Dictionary.com
1841, from train (v.) in the "instruct" sense + -ee.
trainer (n.) Look up trainer at Dictionary.com
c.1600, "one who educates or instructs," agent noun from train (v.). Meaning "one who prepares another for feats requiring physical fitness" is from 1823, originally of horse-trainers.
training (n.) Look up training at Dictionary.com
mid-15c., "protraction, delay," verbal noun from train (v.). From 1540s as "discipline and instruction to develop powers or skills;" 1786 as "exercise to improve bodily vigor." Training wheels as an attachment to a bicycle is from 1953.
traipse (v.) Look up traipse at Dictionary.com
1590s, of uncertain origin, perhaps from dialectal French trepasser "pass over or beyond," from Old French trespasser "cross, traverse, transgress" (see trespass). Or from a source related to Middle Dutch trappen, dialectal Norwegian trappa "to tread, stamp" (see trap (n.)). Liberman points out that it resembles German traben "tramp" "and other similar verbs meaning 'tramp; wander; flee' in several European languages. They seem to have been part of soldiers' and vagabonds' slang between 1400 and 1700. In all likelihood, they originated as onomatopoeias and spread to neighboring languages from Low German." Related: Traipsed; traipsing.
trait (n.) Look up trait at Dictionary.com
late 15c., "shot, missiles;" later "a stroke in drawing, a short line" (1580s), from Middle French trait "line, stroke, feature, tract," from Latin tractus "drawing, drawing out, dragging, pulling," later "line drawn, feature," from past participle stem of trahere "to pull, draw" (see tract (n.1)). Sense of "particular feature, distinguishing quality" in English is first recorded 1752.
traitor (n.) Look up traitor at Dictionary.com
c.1200, "one who betrays a trust or duty," from Old French traitor, traitre "traitor, villain, deceiver" (11c., Modern French traître), from Latin traditor "betrayer," literally "one who delivers," agent noun from stem of tradere "deliver, surrender" (see tradition). Originally usually with a suggestion of Judas Iscariot; especially of one false to his allegiance to a sovereign, government, or cause from late 15c.
traitorous (adj.) Look up traitorous at Dictionary.com
late 14c., "guilty of treason," apparently from Old French traitros "treacherous" (13c.), from traitor (see traitor). Related: Traitorously; traitorousness.
trajectory (n.) Look up trajectory at Dictionary.com
"path described by a body moving under the influence of given forces," 1690s, from Modern Latin trajectorium, from trajectorius "of or pertaining to throwing across," from Latin traiectus "thrown over or across," past participle of traicere "throw across, shoot across," from Latin trans- "across" (see trans-) + icere, combining form of iacere "to throw" (see jet (v.)). Middle French and Middle English had trajectorie as "end of a funnel," from Latin traiectorium.
tram (n.) Look up tram at Dictionary.com
c.1500, "beam or shaft of a barrow or sledge," also "a barrow or truck body" (1510s), Scottish, originally in reference to the iron trucks used in coal mines, probably from Middle Flemish tram "beam, handle of a barrow, bar, rung," a North Sea Germanic word of unknown origin. The sense of "track for a barrow, tramway" is first recorded 1826; that of "streetcar" is first recorded 1879, short for tram-car "car used on a tramway" (1873).
trammel (n.) Look up trammel at Dictionary.com
mid-14c., "net to catch fish" (implied in trammeller "one who fishes with a trammel net"), from Old French tramail "fine-gauged fishnet" (13c.), from Late Latin tremaculum, perhaps meaning "a net made from three layers of meshes," from Latin tri- "three" (see tri-) + macula "a mesh" (see mail (n.2)). Meaning "anything that hinders" is from 1650s, originally "a hobble for a horse" (c.1500). Italian tramaglio, Spanish trasmallo are French loan-words.
trammel (v.) Look up trammel at Dictionary.com
1530s, originally "to bind up (a corpse);" sense of "hinder, restrain" is from 1727, from trammel (n.), a figurative use from the literal sense "bind (a horse's legs) with a trammel" (c.1600). Related: Trammeled; trammeling.
tramp (n.) Look up tramp at Dictionary.com
"person who wanders about, idle vagrant, vagabond," 1660s, from tramp (v). Sense of "steamship which takes cargo wherever it can be traded" (as opposed to one running a regular line) is attested from c.1880. The meaning "promiscuous woman" is from 1922. Sense of "a long, toilsome walk" is from 1786.
tramp (v.) Look up tramp at Dictionary.com
late 14c., "walk heavily, stamp," from Middle Low German trampen "to stamp," from Proto-Germanic *tremp- (cognates: Danish trampe, Swedish trampa "to tramp, stamp," Gothic ana-trimpan "to press upon"), from PIE *der- (1) "to run, walk, step" (see tread (v.)). Related: Tramped; tramping.
trample (v.) Look up trample at Dictionary.com
late 14c., "to walk heavily," frequentative form of tramp (v.). Transitive sense "beat down by continuously treading on" is from mid-15c. Related: Trampled; trampling. As a noun from c.1600.
trampoline (n.) Look up trampoline at Dictionary.com
1798, from Spanish trampolin "springboard," and Italian trampolino, from trampoli "stilts," from a Germanic source (compare Low German trampeln "trample") related to tramp (v.).
trance (n.) Look up trance at Dictionary.com
late 14c., "state of extreme dread or suspense," also "a half-conscious or insensible condition, state of insensibility to mundane things," from Old French transe "fear of coming evil," originally "coma, passage from life to death" (12c.), from transir "be numb with fear," originally "die, pass on," from Latin transire "cross over" (see transient). French trance in its modern sense has been reborrowed from English. As a music genre, from c.1993.
tranche (n.) Look up tranche at Dictionary.com
c.1500, from French tranche "a cutting," from trancher, trencher "to cut," Old French trenchier (see trench). Economic sense is from 1930.
trannie (n.) Look up trannie at Dictionary.com
also tranny "transsexual person," 1983, from transsexual + -ie. In 1960s and '70s the word was used as a slang shortening of transistor radio and in car magazines for transmission.
tranquil (adj.) Look up tranquil at Dictionary.com
mid-15c., a back-formation from tranquility or else from Latin tranquillus "quiet, calm, still." Related: Tranquilly.
tranquility (n.) Look up tranquility at Dictionary.com
also tranquillity, late 14c., from Old French tranquilite "peace, happiness" (12c.), from Latin tranquillitatem (nominative tranquillitas) "quietness, stillness; serenity," from tranquillus "quiet, calm, still," perhaps from trans- "over" (here in its intensive sense of "exceedingly") + a root possibly related to quies "rest" (see quiet (n.)).
tranquilize (v.) Look up tranquilize at Dictionary.com
1620s, from tranquil + -ize. Related: Tranquilized; tranquilizing; tranquilization.
tranquilizer (n.) Look up tranquilizer at Dictionary.com
1800, "that which tranquilizes;" from 1824 as "a sedative" (first reference is to ground ivy), agent noun from tranquilize; in reference to one of a large group of anti-anxiety drugs, it is recorded by 1956.
trans- Look up trans- at Dictionary.com
word-forming element meaning "across, beyond, through, on the other side of, to go beyond," from Latin trans-, from trans (prep.) "across, over, beyond," perhaps originally present participle of a verb *trare-, meaning "to cross," from PIE *tra-, variant of root *tere- (2) "to cross over" (see through). In chemical use indicating "a compound in which two characteristic groups are situated on opposite sides of an axis of a molecule" [Flood].
trans-Atlantic (adj.) Look up trans-Atlantic at Dictionary.com
also transatlantic, 1779, from trans- "through, across" + Atlantic.
trans-oceanic (adj.) Look up trans-oceanic at Dictionary.com
1827, "situated across the ocean," from trans- + oceanic. Meaning "passing over the sea" is recorded from 1868.