Online Etymology Dictionary

translucent (adj.): 1590s, from Latin translucentem (nominative translucens), present participle of translucere "to shine through," from trans- "through" (see trans-) + lucere "to shine" (see light (n.)).
transmigration (n.): c.1300, from Late Latin transmigrationem (nominative transmigratio) "change of country," noun of action from past participle stem of Latin transmigrare "to wander, to migrate," from trans- "over" (see trans-) + migrare "to migrate" (see migration). Originally literal, in reference to the removal of the Jews into the Babylonian captivity; general sense of "passage from one place to another" is attested from late 14c.; sense of "passage of the soul after death into another body" first recorded 1590s.
transmissible (adj.): 1640s, from Latin transmiss-, stem of transmittere (see transmit) + -ible.
transmission (n.): 1610s, "conveyance from one place to another," from Latin transmissionem (nominative transmissio) "a sending over or across, passage," from transmissus, past participle of transmittere "send over or across" (see transmit). Meaning "part of a motor vehicle that regulates power from the engine to the axle" is first recorded 1894.
transmit (v.): c.1400, from Latin transmittere "send across, transfer, pass on," from trans- "across" (see trans-) + mittere "to send" (see mission). Related: Transmitted; transmitting.
transmittal (n.): 1724, from transmit + -al (2).
transmittance (n.): 1855, from transmit + -ance.
transmitter (n.): "apparatus for receiving radio signals," 1934, agent noun from transmit.
transmogrify (v.): "to change completely," 1650s, apparently a perversion of transmigure, from transmigrate, perhaps influenced by modify. Related: Transmogrified; transmogrifying.
transmutation (n.): late 14c., from Old French transmutation (12c.), from Late Latin transmutationem (nominative transmutatio) "a change, shift," noun of action from Latin transmutare "change from one condition to another," from trans- "thoroughly" (see trans-) + mutare "to change" (see mutable). A word from alchemy.
transmute (v.): early 15c., from Latin transmutare, from trans- (see trans-) + mutable). Related: Transmuted; transmuting.
transnational (adj.): 1921, from trans- + national.
transnationalism (n.): 1921, from transnational + -ism.
transom (n.): mid-14c., transeyn "crossbeam spanning an opening, lintel," probably by dissimilation from Latin transtrum "crossbeam" (especially one spanning an opening), from trans- "across" (see trans-) + instrumental suffix -trum. Meaning "small window over a door or other window" is first recorded 1844.
transparency (n.): 1610s, "condition of being transparent," from Medieval Latin transparentia, from transparentem (see transparent). Meaning "that which is transparent" is from 1590s; of pictures, prints, etc., from 1785; in photography from 1866.
transparent (adj.): early 15c., from Medieval Latin transparentem (nominative transparens), present participle of transparere "show light through," from Latin trans- "through" (see trans-) + parere "come in sight, appear" (see appear). Figurative sense of "easily seen through" is first attested 1590s. The attempt to back-form a verb transpare (c.1600) died with the 17c.
transpiration (n.): early 15c., from Medieval Latin transpirationem, noun of action from transpirare (see transpire).
transpire (v.): 1590s, "pass off in the form of a vapor or liquid," from Middle French transpirer (mid-16c.), from Latin trans- "through" (see trans-) + spirare "to breathe" (see spirit). Figurative sense of "leak out, become known" is recorded from 1741, and the erroneous meaning "take place, happen" is almost as old, being first recorded 1755. Related: Transpired; transpiring.
transplant (v.): mid-15c., from Late Latin transplantare "plant again in a different place," from Latin trans- "across" (see trans-) + plantare "to plant" (see plant). Extended to people (1550s) and then to organs or tissue (1786). The noun, in reference to plants, is recorded from 1756; in reference to surgical transplanting of human organs or tissue it is first recorded 1951, but not in widespread use until Christiaan Barnard performed the world's first successful heart transplant in 1967 at Groote Schuur Hospital, Cape Town, South Africa. Meaning "person not native to his place of residence" is recorded from 1961.
transponder (n.): 1945, from trans(mit) + (res)pond + agent noun suffix -er (1).
transport (v.): late 14c., from Old French transporter "carry or convey across" (14c.), from Latin transportare, from trans- "across" (see trans-) + portare "to carry" (see port (n.1)). Sense of "carry away with strong feelings" is first recorded c.1500. Meaning "to carry away into banishment" is recorded from 1660s. The noun is attested from mid-15c., originally "mental exaltation;" sense of "means of transportation" is recorded from 1690s.
transportation (n.): 1530s, "act of transporting," noun of action from transport (v.). Middle English used verbal noun transporting (early 15c.). In the sense of "means of conveyance" it is first recorded 1853.
transpose (v.): late 14c., from Old French transposer (14c.), from Latin transponere (past participle transpositus) "to place over," from trans- "over" (see trans-) + ponere "to put, place" (see position). Form altered in French on model of poser "to put, place." Sense of "put music in a different key" is from c.1600. Related: Transposed; transposing.
transposition (n.): 1530s, from French transposition or directly from Medieval Latin transpositionem, noun of action from past participle stem of transponere (see transpose).
transsexual: 1957 (adj. and n.), from trans- + sexual, and cf. transsexualism.
transsexualism (n.): "intense desire to change one's sexual status, including the anatomical structure," 1953, coined by U.S. physician Harry Benjamin (1885-1986) from trans- + sexual. Transsexuality is recorded from 1941, but was used at first to mean "homosexuality" or "bisexuality."
transubstantiation (n.): late 14c., "change of one substance to another," from Medieval Latin trans(s)ubstantiationem (nominative trans(s)ubstantio), noun of action from trans(s)ubstantiare "to change from one substance into another," from Latin trans- "across" (see trans-) + substantiare "to substantiate," from substania "substance" (see substance). Ecclesiastical sense in reference to the Eucharist first recorded 1530s.
transversal (adj.): mid-15c., from Medieval Latin transversalis (mid-13c.), from transvers-, stem of transvertere (see transverse).As a noun, from 1590s.
transverse (adj.): "lying across," early 15c. (earlier transversary, c.1400), from Latin transversus "turned or directed across," past participle of transvertere "turn across," from trans- "across" (see trans-) + vertere "to turn" (see versus). The verb transvert is recorded from late 14c.
transvestite (n.): "person with a strong desire to dress in clothing of the opposite sex," 1922, from German Transvestit (1910), coined from Latin trans- "across" (see trans-) + vestire "to dress, to clothe" (see wear (v.)). Cf. also travesty, which is the same word, older, and passed through French and Italian. Shortened form trannie first recorded 1983 (in 1960s this was used as a slang shortening of transistor radio). Transvestism is first attested 1928.
trap (v.): c.1400, "ensnare (an animal), catch in a trap; encircle; capture," from trap (n.) or from Old English betræppan. Figurative use is slightly earlier (late 14c.). Related: Trapped; trapping.
trap (n.): "contrivance for catching unawares," late Old English træppe "snare, trap," from Proto-Germanic *trap- (cf. Middle Dutch trappe "trap, snare"), related to Germanic words for "stair, step, tread" (cf. Middle Dutch, Middle Low German trappe, treppe, German Treppe "step, stair"). Probably akin to Old French trape, Spanish trampa "trap, pit, snare," but the exact relationship is uncertain. The connecting notion seems to be "that on which an animal steps." Sense of "deceitful practice, trickery" is first recorded c.1400. Sense in speed trap recorded from 1906. Slang meaning "mouth" is from 1776. Trap door "door in a floor or ceiling" (often hidden and leading to a passageway or secret place) is first attested late 14c.
trapeze (n.): 1861, from French trapèze, from Late Latin trapezium (see trapezium), probably because the crossbar, the ropes and the ceiling formed a trapezium.
trapezium (n.): 1560s, from Late Latin trapezium, from Greek trapezion "irregular quadrilateral," literally "a little table," diminutive of trapeza "table," from tra- "four" (see four) + peza "foot, edge," related to pous (see foot (n.)). Before 1540s, Latin editions of Euclid used the Arabic word helmariphe. As the name of a bone in the wrist, it is recorded from 1840.
trapezius (n.): 1704, from Modern Latin trapezius (musculus), masc. adjective from trapezium (see trapezium).
trapezoid (n.): 1706, "a trapezium," from Modern Latin trapezoides, from Late Greek trapezoeides (Proclus), special use by Euclid of Greek trapezoeides "trapezium-shaped," from trapeza, literally "table" (see trapezium), + -oeides "shaped" (see -oid). Technically, a quadrilateral figure with no two sides parallel. But in English since c.1800, often confused with trapezium in its sense of "a quadrilateral figure having only two sides parallel."
trapper (n.): "one who traps animals" (for fur, etc.), 1768, agent noun from trap (v.).
trappings (n.): "ornamental covering for a horse," late 14c., from Middle English trappe "cloth for a horse" (c.1300), later "personal effects" (mid-15c.), alteration of Middle French drap "cloth" (see drape (n.)).
Trappist (n.): 1814, from French trappiste, Cistercian monk of reformed order established 1664 by abbot De Rancé of La Trappe in Normandy.
traps (n.1): "expanse of dark igneous rock," 1794, from Swedish trapp (1766), from trappa "stair," related to Middle Low German trappe "staircase" (see trap (n.)). So called from the step-like appearance of the rock.
traps (n.2): "drums, cymbals, bells, etc.," 1925, from earlier trap drummer (1903) "street musician who plays a drum and several other instruments at once," perhaps from traps "belongings" (1813), shortened form of trappings.
trash (n.): "anything of little use or value," late 14c., perhaps from a Scandinavian source (cf. Old Norse tros "rubbish, fallen leaves and twigs," Norwegian dialectal trask "lumber, trash, baggage," Swedish trasa "rags, tatters"), of unknown origin. Applied to ill-bred persons or groups from 1604 ("Othello"). Applied to domestic refuse or garbage in 1906 (American English).
trash (v.): "to discard as worthless," 1895, from trash (n.); in the sense of "destroy, vandalize" it is attested from 1970; extended to "criticize severely" in 1975. Related: Trashed; trashing.
trashy (adj.): "worthless," 1610s, from trash (n.) + -y (2). Related: Trashiness.
trattoria (n.): "Italian restaurant," 1832, from Italian trattoria, from trattore "host, keeper of an eating house," from trattare "to treat," from Latin tractare, frequentative of trahere (past participle tractus) "to draw" (see tract (n.1)).
trauma (n.): 1650s (implied in traumatic), "physical wound," from Greek trauma "wound," from PIE *tro-, *trau-, from root *tere- "to rub, turn" (see throw (v.)). Sense of "psychic wound, unpleasant experience which causes abnormal stress" is implied in traumatic, in psychological jargon 1889.
traumatic (adj.): 1650s, from Late Latin traumaticus, from Greek traumatikos "pertaining to a wound," from trauma (see trauma).
traumatise (v.): chiefly British English spelling of traumatize; for suffix, see -ize. Related: Traumatised; traumatising.
traumatize (v.): 1903, of physical wounds; 1949 in the psychological sense, from Greek traumat-, stem of trauma (see trauma).
travail (n.): "labor, toil," mid-13c., from Old French travail "suffering or painful effort, trouble" (12c.), from travailler "to toil, labor," originally "to trouble, torture," from Vulgar Latin *tripaliare "to torture," from *tripalium (in Late Latin trepalium) "instrument of torture," probably from Latin tripalis "having three stakes" (from tria, tres "three" + palus "stake"), which sounds ominous, but the exact notion is obscure. The verb is recorded from late 13c.