Online Etymology Dictionary

transmit (v.): c. 1400, from Latin transmittere "send across, cause to go 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.): 1786, from transmit + -ance.
transmitter (n.): 1727, "one who transmits," agent noun from transmit. In telegraphy from 1844. Meaning "apparatus for transmitting radio signals" is from 1934.
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 transmutacion "transformation, change, metamorphosis" (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.): late 14c., "transform the appearance of," from Latin transmutare "to change" (see transmutation). Related: Transmuted; transmuting.
transnational (adj.): 1921, from trans- + national (adj.). Related: Transnationally.
transnationalism (n.): 1921, from transnational + -ism.
transom (n.): late 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. Related: Transparence.
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. Related: Transparently.
transpiration (n.): early 15c., from Medieval Latin transpirationem (nominative transpiratio), noun of action from transpirare (see transpire).
transpire (v.): 1590s, "pass off in the form of a vapor or liquid," from Middle French transpirer (16c.), from Latin trans- "through" (see trans-) + spirare "to breathe" (see spirit (n.)). 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 (v.)). Extended to people (1550s) and then to organs or tissue (1786). Related: Transplanted; transplanting.
transplant (n.): 1756, in reference to plants, from transplant (v.); 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.
transplantation (n.): c. 1600, from French transplantation, noun of action from transplanter (v.), from Late Latin transplantare (see transplant (v.)).
transponder (n.): 1945, from trans(mit) + (res)pond + agent noun suffix -er (1).
transpontine (adj.): 1844, in a London context in reference to the area south of the Thames, from Latin trans- (see trans-) + pontine, from stem of pons "bridge" (see pons).
transport (v.): late 14c., "convey from one place to another," from Old French transporter "carry or convey across; overwhelm (emotionally)" (14c.) or directly from Latin transportare "carry over, take across, convey, remove," 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.
transport (n.): mid-15c., originally "mental exaltation;" sense of "means of transportation, carriage, conveyance" is recorded from 1690s; from transport (v.).
transportable (adj.): 1580s, from transport (v.) + -able.
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 "transfer, remove; present, render symbolically" (14c.), from Latin transponere (past participle transpositus) "to place over, set over," from trans- "over" (see trans-) + ponere "to put, place" (past participle positus; see position (n.)). 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 Middle French transposition or directly from Medieval Latin transpositionem (nominative transpositio), noun of action from past participle stem of transponere (see transpose).
transsexual: 1957 (adj. and n.), from trans- + sexual, and compare 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." In the current sense from 1955.
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.): "running or lying across," mid-15c., from Medieval Latin transversalis (13c.), from transvers-, stem of transvertere (see transverse). Earlier in the same sense was transversary (c. 1400). As a noun, from 1590s. Related: Transversally.
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.)). As an adjective from 1925. Transvestism is first attested 1928. Also see travesty, which is the same word, older, and passed through French and Italian; it generally has a figurative use in English, but has been used in the literal sense of "wearing of the clothes of the opposite sex" (often as a means of concealment or disguise) since at least 1823, and travestiment "wearing of the dress of the opposite sex" is recorded by 1832. Among the older clinical words for it was Eonism "transvestism, especially of a man" (1913), from Chevalier Charles d'Eon, French adventurer and diplomat (1728-1810) who was anatomically male but later in life lived and dressed as a woman (and claimed to be one).
Transylvania: literally "beyond the forest," from Medieval Latin, from trans "beyond" (see trans-) + sylva (see sylvan). So called in reference to the wooded mountains that surround it.
trap (n.): "contrivance for catching unawares," late Old English træppe, treppe "snare, trap," from Proto-Germanic *trep- (source also of Middle Dutch trappe "trap, snare"), related to Germanic words for "stair, step, tread" (Middle Dutch, Middle Low German trappe, treppe, German Treppe "step, stair," English tread (v.)), and probably literally "that on or into which one steps," from PIE *dreb-, extended form of root *der- (1), an assumed base of words meaning "to run, walk, step." Probably akin to Old French trape, Spanish trampa "trap, pit, snare," but the exact relationship is uncertain.

Sense of "deceitful practice, device or contrivance to betray one" is first recorded c. 1400. Meaning "U-shaped section of a drain pipe" is from 1833. Slang meaning "mouth" is from 1776. Speed trap recorded from 1908. Trap door "door in a floor or ceiling" (often hidden and leading to a passageway or secret place) is first attested late 14c.
trap (v.): late 14c., "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.
trapeze (n.): swing with a cross-bar, used for feats of strength and agility, 1861, from French trapèze, from Late Latin trapezium (see trapezium), probably because the crossbar, the ropes and the ceiling formed a trapezium.
The French, to whose powers of invention (so long as you do not insist upon utility) there is no limit, have invented for the world the Trapeze .... ["Chambers's Journal," July 6, 1861]
trapezium (n.): 1560s, from Late Latin trapezium, from Greek trapezion "irregular quadrilateral," literally "a little table," diminutive of trapeza "table, dining table," from tra- "four" (see four) + peza "foot, edge," related to pous, from PIE root *ped- (1) "a foot" (see foot (n.)). Before 1540s, Latin editions of Euclid used the Arabic-derived word helmariphe. As the name of a bone in the wrist, it is recorded from 1840.
trapezius (n.): muscle over the back of the neck, 1704, from Modern Latin trapezius (musculus), masc. adjective from trapezium (see trapezium). So called from the shape they form.
trapezoid (n.): 1706, "a trapezium," from Modern Latin trapezoides, from Late Greek trapezoeides, noun use by Euclid of Greek trapezoeides "trapezium-shaped," from trapeza, literally "table" (see trapezium), + -oeides "shaped" (see -oid). Technically, a plane four-sided 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 sides parallel and two not."
trapezoidal (adj.): 1796, from trapezoid + -al (1).
trapper (n.): "one who traps animals" (for fur, etc.), 1768, agent noun from trap (v.).
trappings (n.): late 14c., "horse-cloth," from Middle English trappe "ornamental 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 Armand Jean le Bouthillier de Rancé (1626-1700) of La Trappe in Normandy.
traps (n.1): "expanse of dark igneous rock," 1794, from Swedish trapp (Torbern Bergman, 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.): late 14c., "thing of little use or value, waste, refuse, dross," perhaps from a Scandinavian source (compare 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"), and especially of poor whites in the U.S. South by 1831. Applied to domestic refuse or garbage from 1906 (American English). Trash-can attested from 1914. To trash-talk someone or something is by 1989.
trash (v.): "to discard as worthless," 1859, 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, resembling trash," 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.): 1690s, "physical wound," medical Latin, from Greek trauma "a wound, a hurt; a defeat," from PIE *trau-, extended form of root *tere- (1) "to rub, turn," with derivatives referring to twisting, piercing, etc. (see throw (v.)). Sense of "psychic wound, unpleasant experience which causes abnormal stress" is from 1894.
traumatic (adj.): 1650s, from French traumatique and directly from Late Latin traumaticus, from Greek traumatikos "pertaining to a wound," from trauma (genitive traumatos; see trauma). Psychological sense is from 1889. Related: Traumatically.