Online Etymology Dictionary

top-heavy (adj.): 1530s, from top (n.1) + heavy.
top-notch (adj.): also top notch, 1848, from top (n.1) + notch (n.). Figurative of the "highest point" of something, but the exact mechanical image is uncertain.
top-sider (n.): kind of casual shoe, 1937, from topside in nautical sense of "upper deck of a ship," where the rubber soles would provide good traction.
topaz (n.): colored crystalline gem, late 13c., from Old French topace (11c.), from Latin topazus, from Greek topazos, topazion, of obscure origin. Pliny says it was named for a remote island in the Red or Arabian Sea, where it was mined, but this might be folk etymology from Greek topazein "to divine, to try to locate;" linguists conjecture a connection with Sanskrit tapas "heat, fire." In the Middle Ages used for almost any yellow stone. To the Greeks and Romans, possibly yellow olivine or yellow sapphire. In modern science, fluo-silicate of aluminum.
tope (v.): "to drink heavily," 1650s, of unknown origin, perhaps ultimately from Italian toppa "done!" a word signifying acceptance of a bet.
Topeka: city in Kansas, U.S.A., from Kansa (Siouan), literally "a good place to dig potatoes."
toper (n.): 1670s, from tope!, exclamation used in drinking (1650s), from French or Italian, originally a word of acceptance in a wager, etc. Cf. tope (v.).
topiary (adj.): 1590s, from Latin topiarius "of or pertaining to ornamental gardening," from topia "ornamental gardening," from Greek topia, plural of topion, originally "a field," diminutive of topos "place" (see topos). The noun is first recorded 1908, from the adjective.
topic (n.): 1630s, "argument suitable for debate," singular form of "Topics" (1560s), the name of a work by Aristotle on logical and rhetorical generalities, from Latin Topica, from Greek Ta Topika, literally "matters concerning topoi," from topoi "commonplaces," neuter plural of topikos "commonplace, of a place," from topos "place" (see topos). The meaning "matter treated in speech or writing, subject, theme" is first recorded 1720.
topical (adj.): 1580s, from topic + -al (1). Medical sense is from c.1600. Meaning "of or pertaining to topics of the day" is from 1873.
topless (adj.): "bare-breasted," 1966 (earlier it was used of men's bathing suits, 1937); from top (n.1) + -less.
topography (n.): early 15c., from Late Latin topographia, from Greek topographia "a description of a place," from topographos "describing a place" (as a noun, "one who is skilled in topography"), from topos "place" (see topos) + graphein "to write" (see -graphy).
topology (n.): 1610s (implied in topological), from topo-, comb. form of Greek topos "place" (see topos) + -logy.
toponym (n.): 1939, from comb. form of Greek topos "place" (see topos) + -onym "name" (see name (n.)). Toponymy "study of place names" is from 1876.
topos (n.): 1948, from Greek topos, literally "place."
topper (n.): "the best (of anything)," 1709, originally slang, agent noun from top (v.).
topping (n.): "top layer," 1839, verbal noun from top (v.).
topple (v.): 1580s, "tumble down," earlier "to tumble or roll about" (1540s), from top (v.) + frequentative suffix -le. Related: Toppled; toppling.
tops (n.): "the best," 1935, from top (n.1).
topsoil (n.): 1836, from top (n.1) + soil (n.).
topsy-turvy (adv., adj.): 1520s, "but prob. in popular use from an earlier period" [OED], likely from tops, plural of top (n.1) "highest point" + obsolete terve "turn upside down, topple over," from Old English tearflian "to roll over, overturn," from Proto-Germanic *terbanan (cf. Old High German zerben "to turn round"). The "Century Dictionary" (1902) calls it "A word which, owing to its popular nature, its alliterative type, and to ignorance of its origin, leading to various perversions made to suggest some plausible origin, has undergone, besides the usual variations of spelling, extraordinary modifications of form." It lists 31 variations.
toque (n.): kind of round hat, c.1500, from Middle French toque (15c.), from Spanish toca "woman's headdress," possibly from Arabic *taqa, from Old Persian taq "veil, shawl."
tor (n.): "high, rocky hill," Old English torr "tower, rock." Obviously cognate with Gaelic torr "lofty hill, mound," Old Welsh twrr "heap, pile;" and probably ultimately from Latin turris "high structure" see tower (n.)). But sources disagree on whether the Celts borrowed it from the Anglo-Saxons or the other way round.
Torah (n.): "the Pentateuch," 1570s, from Hebrew torah, literally "instruction, law," verbal noun from horah "he taught, showed."
torch (n.): late 13c., from Old French torche, originally "twisted thing," hence "torch formed of twisted tow dipped in wax," probably from Vulgar Latin *torca, alteration of Late Latin torqua, variant of classical Latin torques "collar of twisted metal," from torquere "to twist" (see thwart). In Britain, also applied to the battery-driven version (in U.S., flashlight). Torch song is 1927 ("My Melancholy Baby," performed by Tommy Lyman, is said to have been the first so called), from carry a torch "suffer an unrequited love" (also 1927), an obscure notion from Broadway slang.
torch (v.): "set fire to," 1931, from torch (n.). Related: Torched; torching.
torcher (n.): "torch-carrier," c.1600; see torch (n.). Meaning "torch singer" attested by 1940.
torchiere (n.): also torchere, 1910, from French torchère, from torche (see torch (n.)).
toreador (n.): "bullfighter," 1610s, from Spanish toreador, from torear "to fight in a bullfight," from toro "bull," from Latin taurus (see steer (n.)).
Tori: fem. proper name, short for Victoria.
toric (adj.): 1890, Latin torus (see torus) + -ic.
torii (n.): singular and plural, "gateway to a Shinto temple," Japanese, from tori "bird" + i "to sit, to perch."
torment (n.): late 13c., "inflicting of torture," also "state of great suffering," from Old French tourment (11c.), from Latin tormentum "twisted sling, rack," related to torquere "to twist" (see thwart).
torment (v.): late 13c., from Old French tormenter (12c.), from Latin tormentare, from tormentum (see torment (n.)). Related: Tormented; tormenting.
tormentor (n.): late 13c., from Anglo-French tormentour, Old French tourmenteur, agent noun of Latin tormentare (see torment (v.)).
torn: past participle of tear (v.); from Old English getoren.
tornado (n.): 1550s, navigator's word for violent windy thunderstorm in the tropical Atlantic, probably a mangled borrowing from Spanish tronada "thunderstorm," from tronar "to thunder," from Latin tonare "to thunder" (see thunder). Metathesis of -o- and -r- in modern spelling influenced by Spanish tornar "to twist, turn," from Latin tornare "to turn." Meaning "extremely violent whirlwind" is first found 1620s.
toro (n.): "bull," 1650s, from Spanish toro "bull," from Latin taurus (see steer (n.)).
Toronto: city in Ontario, Canada, founded 1793 as York, renamed 1834 for a native village that appears on a 1656 map as Tarantou. from an Iroquoian source, original form and sense unknown; perhaps taron-to-hen "wood in the water," or Huron deondo "meeting place."
torpedo (n.): 1520s, "electric ray," from Latin torpedo, originally "numbness" (from the effect of being jolted by the ray's electric discharges), from torpere "be numb" (see torpor). The sense of "explosive device used to blow up enemy ships" is first recorded 1776, as a floating mine; the self-propelled version is from 1860s.
torpedo (v.): 1873, from torpedo (n.). Figurative sense attested from 1895. Related: Torpedoed; torpedoing.
torpid (adj.): 1610s, from Latin torpidus "benumbed," from torpere "be numb or stiff" (see torpor).
torpor (n.): c.1600, from Latin torpor "numbness," from torpere "be numb," from PIE root *ster- "stiff" (cf. Old Church Slavonic trupeti, Lithuanian tirpstu "to become rigid;" Greek stereos "solid;" Old English steorfan "to die;" see sterile).
torque (n.): "rotating force," 1884, from Latin torquere "to twist" (see thwart). The verb is attested from 1954. The word also is used (since 1834) by antiquarians and others as a term for the twisted metal necklace worn anciently by Gauls, Britons, Germans, etc., from Latin torques in this sense. Earlier it had been called in English torques (1690s).
torr (n.): unit of pressure, 1949, named for Italian physicist Evangelista Torricelli (1608-1647), inventor of the barometer.
torrent (n.): c.1600, from French torrent, from Latin torrentem (nominative torrens) "rushing stream," originally "roaring, boiling, burning, parching," present participle of torrere "to parch" (see terrain). Sense of "any onrush" (of words, feelings, etc.) first recorded 1640s.
torrential (adj.): 1849; see torrent + -al (1).
torrid (adj.): 1580s, in torrid zone "region of the earth between the tropics," from Latin torrida zona, from fem. of torridus "dried with heat, scorching hot," from torrere "to parch," from PIE root *ters- "to dry" (see terrain). Sense of "very hot" is first attested 1610s.
torsion (n.): early 15c., "wringing pain in the bowels," from Old French torsion (early 14c.), from Late Latin torsionem (nominative torsio) "a wringing or gripping," from Latin tortionem (nominative tortio) "torture, torment," noun of action from past participle stem of torquere "to twist" (see thwart). Meaning "action or process of twisting as by opposing forces" is first recorded 1540s.
torso (n.): 1797, from Italian torso "trunk of a statue," originally "stalk, stump," from Vulgar Latin *tursus, from Latin thyrsus "stalk, stem," from Greek thyrsos (see thyrsus).