Online Etymology Dictionary

talus (n.1): "anklebone," 1690s, from Latin talus "ankle, anklebone, knucklebone" (plural tali), related to Latin taxillus "a small die, cube" (they originally were made from the knucklebones of animals).
talus (n.2): "slope," 1640s, from French talus (16c.), from Old French talu "slope, mound, small hill" (12c.), probably from Gallo-Roman *talutum, from Latin talutium "a slope or outcrop of rock debris," perhaps of Celtic origin (compare Welsh, Breton tal "forehead, brow").

OED, however, suggests derivation from root of talus (n.1) in the sense of "heel" which developed in its Romanic descendants. Mainly used of military earthwork at first; meaning "sloping mass of rocky fragments that has fallen from a cliff" is first recorded 1830.
tam-o'-shanter (n.): c. 1840, type of bonnet formerly worn by Scottish plowmen, from Tam O'Shanter "Tom of Shanter," name of hero in a poem of the same name by Robert Burns, written 1790. The woolen cap became fashionable for ladies c. 1887.
tamale (n.): 1856, false singular from tamales (1690s), from American Spanish tamales, plural of tamal, from Nahuatl tamal, tamalli, a food made of Indian corn and meat.
tamarack (n.): also tamarac, North American black larch, 1805, probably of Algonquian origin (compare synonymous hackmatack, 1792, from a source akin to Abenaki akemantak "a kind of supple wood used for making snowshoes"), but the etymology is unclear.
tamarind (n.): c. 1400, "fruit of the tamarind tree, used medicinally," ultimately from Arabic tamr hindi, literally "date of India," from hind "India." First element cognate with Hebrew tamar "palm tree, date palm." Of the tree itself, from 1610s.
tamarisk (n.): southern European evergreen shrub, c. 1400, from Late Latin tamariscus, variant of tamarix, of unknown origin, probably a borrowing from a non-Indo-European language; perhaps Semitic and related to Hebrew tamar "palm tree, date palm" (see tamarind).
tambourine (n.): 1782, in the modern sense of "parchment-covered hoop with pieces of metal attached;" earlier "a small drum" (1570s), from French tambourin "long narrow drum used in Provence," diminutive of tambour "drum," altered by influence of Arabic tunbur "lute," from Old French tabour (see tabor).

The sense evolutions present some difficulties, and in some 17c. and early 18c. references it is difficult to say what sort of instrument is intended. Earlier names for this type of instrument were tambour de basque (1680s), also timbre and timbrel. Tambour itself is attested in English from late 15c., and Shakespeare has tabourine.
tame (adj.): early Middle English tame "in a state of subjection, physically subdued, restrained in behavior" (c. 1200); of animals "domesticated, reclaimed from wildness," also, of persons, "meek, gentle-natured, compliant, intent on homely or domestic activities" (mid-13c.), from oblique forms of Old English tom, tam "domesticated, docile," from Proto-Germanic *tamaz (source also of Old Norse tamr, Old Saxon, Old Frisian, Middle Low German, Middle Dutch tam, Old High German zam, German zahm "tame," Gothic tamjan "to tame"), from PIE *deme- "to constrain, to force, to break (horses)" (source also of Sanskrit damayati "tames;" Persian dam "a tame animal;" Greek daman "to tame, subdue," dmetos "tame;" Latin domare "to tame, subdue;" Old Irish damnaim "I tie up, fasten, I tame, subdue").

A possible ulterior connection is with PIE *dem- "house, household" (see domestic (adj.)). Meaning "spiritless, weak, dull, uninspiring, insipid" is recorded from c. 1600. Related: Tamely; tameness.
tame (v.): mid-14c., from tame (adj.), or altered by the form of the adjective from Old English temian "subdue, make tame," from Proto-Germanic *tamjan- (source also of Old Norse temja, Old Frisian tema, Middle Dutch temmen, Old High German zemmen, German zähmen, Gothic tamjan). Related: Tamed; taming.
Tamil: Dravidian people and language of southern India, 1734, from Pali Damila, from Sanskrit Dramila, variant of Dravida (see Dravidian).
Tammany: in 19c. American English political jargon synonymous with "Democratic Party in New York City," hence, late 19c., proverbial for "political and municipal corruption," from Tammany Hall, on 14th Street, headquarters of a social club incorporated 1789, named for Delaware Indian chief Tamanen, who sold land to William Penn in 1683 and '97. Around the time of the American Revolution he was popularly canonized as St. Tammany and taken as the "patron saint" of Pennsylvania and neighboring colonies, sometimes of the whole of America. He was assigned a feast day (May 1 Old Style, May 12 New Style) which was celebrated with festivities that raised money for charity, hence the easy transfer of the name to what was, at first, a benevolent association. The club's symbol was a tiger.
Tammuz (n.): Babylonian and Assyrian god (identified with Adon), according to Klein's sources probably from Babylonian Du'uzu, contraction of Dumu-zi "the son who rises," also interpeted as "the faithful son."
tamp (v.): 1819, "to fill (a hole containing an explosive) with dirt or clay before blasting," a workmen's word, perhaps a back-formation from tampion, that word being mistaken as a present participle (*tamping).
Tampa: city in Florida, U.S.A., probably from the name of a Calusa village, of unknown origin.
tamper (v.): "meddle, interfere," 1560s, figurative use of tamper "to work in clay, etc., so as to mix it thoroughly," probably originally a variant of temper (v.), which is how it often was spelled at first. Perhaps it is a dialectal workmen's pronunciation. Related: Tampered; tampering.
tamper (n.): "one who or that which tamps," 1864, agent noun from tamp (v.).
tamperproof (adj.): also tamper-proof, 1886, from tamper (v.) + proof.
tampion (n.): early 15c., "plug, bung," from Middle French tampon (15c.), nasalized variant of Old French tapon "piece of cloth to stop a hole" (14c.), a suffixed form of Frankish *tappo "stopper, plug," related to Old High German zapfo and Old English tæppa "stopper" (see tap (n.1)). Meaning "wooden plug for the muzzle of a gun" (to keep out rain or seawater) is recorded from 1620s.
tampon (n.): "plug of cotton to stanch a flow of blood (especially from the vagina)," 1848, from French tampon, from Middle French tampon "plug" (see tampion). Tampax, proprietary name registered in U.S. 1932, is based on tampon.
tan (v.): late Old English tannian "to convert hide into leather" (by steeping it in tannin), from Medieval Latin tannare "tan, dye a tawny color" (c.900), from tannum "crushed oak bark," used in tanning leather, probably from a Celtic source (such as Breton tann "oak tree"). The meaning "make brown by exposure to the sun" (as tanning does to hides) first recorded 1520s; intransitive sense also from 1520s. Of persons, not considered an attractive feature until 20c.; in Shakespeare, "to deprive of the freshness and beauty of youth" (Sonnet CXV). As an adjective from 1620s. To tan (someone's) hide in the figurative sense is from 1660s. Related: Tanned; tanning. German Tanne "fir tree" (as in Tannenbaum) might be a transferred meaning from the same Celtic source.
tan (n.): "bronze color imparted to skin by exposure to sun," 1749, see tan (v.). Earlier as "substance made of crushed bark used in making leather" (c. 1600). As a simple name for a brownish color, in any context, it is recorded from 1888. The adjective meaning "of the color of tanned leather" is recorded from 1660s. Tan-line attested from 1979.
tanager (n.): small American oscine bird, 1844, earlier tanagra (1610s), from Modern Latin tanagra, alteration of Portuguese tangara, from Tupi (Brazil) tangara, a bird name of uncertain meaning.
tandem (n.): 1785, "carriage pulled by horses harnessed one behind the other" (instead of side-by-side), jocular use of Latin tandem "at length (of time), at last, so much," from tam "so" (from PIE *tam-, adverbial form of demonstrative pronoun root *-to-; see -th (1)) + demonstrative suffix -dem. "Probably first in university use" [Century Dictionary]. Transferred by 1884 to bicycles with two seats. In English as an adverb from 1795; as an adjective from 1801.
tandoor (n.): 1660s, from Turkish pronunciation of Persian and Arabic tannur "oven, portable furnace" (see tandoori).
tandoori (adj.): in reference to a type of Indian cooking, 1958, from adjectival form of Urdu or Punjabi tandur "cooking stove," from Turkish tandur, from Turkish pronunciation of Arabic and Persian tannur "oven, portable furnace," of Semitic origin. As a noun by 1969.
tang (n.): mid-14c., "serpent's tongue" (thought to be a stinging organ), later "sharp extension of a metal blade" (1680s), from a Scandinavian source akin to Old Norse tangi "spit of land; pointed end by which a blade is driven into a handle," from Proto-Germanic *tang-, from PIE *denk- "to bite" (see tongs). Influenced in some senses by tongue (n.). Figurative sense of "a sharp taste" is first recorded mid-15c.; that of "suggestion, trace" is from 1590s. The fish (1734) so called for their spines.
tangelo (n.): "hybrid of a tangerine and a pomelo," 1904, the word formed like the fruit.
tangent (adj.): 1590s, "meeting at a point without intersecting," from Latin tangentem (nominative tangens), present participle of tangere "to touch," from PIE root *tag- "to touch, to handle; border on; taste, partake of; strike, hit;" figuratively "affect, impress; trick, cheat; mention, speak of" (source also of Latin tactus "touch;" Greek tassein "to arrange," tetagon "having seized;" Old English þaccian "stroke, strike gently"). First used by Danish mathematician Thomas Fincke in "Geomietria Rotundi" (1583). Extended sense of "slightly connected with a subject" is first recorded 1825. Related: Tangence; tangency.
tangent (n.): 1590s as a geometric function, from tangent (adj.). From 1650s as "a tangent line." Figurative use of off on a tangent is from 1771.
tangental (adj.): 1742, from tangent (adj.) + -al (1). Related: Tangentally.
tangential (adj.): 1620s, see tangent (adj.) + -ial. Figurative sense of "divergent, erratic" is from 1787; that of "slightly connected" is from 1825. Related: Tangentially.
tangerine (n.): 1842, from tangerine orange (1820) "an orange from Tangier," seaport in northern Morocco, from which it was imported to Britain originally. As an adjective meaning "from Tangier," attested from 1710, probably from Spanish tangerino. As a color name, attested from 1899.
tangible (adj.): 1580s, "capable of being touched," from Middle French tangible and directly from Late Latin tangibilis "that may be touched," from Latin tangere "to touch" (see tangent (adj.)). Sense of "material" (as in tangible reward) is first recorded 1610s; that of "able to be realized or dealt with" is from 1709. Related: Tangibly.
Tangier: port city of Morocco, Latin Tinge, said to be named for Tingis, daughter of Atlas, but probably from Semitic tigisis "harbor." In English often Tangiers, by influence of Algiers.
tangle (v.): mid-14c., nasalized variant of tagilen "to involve in a difficult situation, entangle," from a Scandinavian source (compare dialectal Swedish taggla "to disorder," Old Norse þongull "seaweed"), from Proto-Germanic *thangul- (source also of Frisian tung, Dutch tang, German Tang "seaweed"); thus the original sense of the root evidently was "seaweed" as something that entangles (itself, or oars, or fishes, or nets). "The development of such a verb from a noun of limited use like tangle 1 is somewhat remarkable, and needs confirmation" [Century Dictionary]. In reference to material things, from c. 1500. Meaning "to fight with" is American English, first recorded 1928. Related: Tangled; tangling. Tanglefoot (1859) was Western American English slang for "strong whiskey."
tangle (n.): 1610s, "a tangled condition, a snarl of threads," from tangle (v.).
tango (n.): syncopated ballroom dance, 1913 (the year it became a rage in Britain and America), from Argentine Spanish tango, originally the name of an African-South American drum dance, probably from a Niger-Congo language (compare Ibibio tamgu "to dance"). Phrase it takes two to tango was a song title from 1952. As a verb from 1913. Related: Tangoed.
It is hardly a year ago since the Tango reached this country from South America by way of Paris. It was at first no more than a music-hall freak. But some of those mysterious people who inspire new social fashions were attracted by its sinuous movements and the strange backward kick, and this year it made its way into private houses as well as public ball rooms. [The Living Age, Dec. 13, 1913]

"I need not describe the various horrors of American and South American negroid origin. I would only ask hostesses to let one know what houses to avoid by indicating in some way on their invitation cards whether the 'turkey-trot,' the 'Boston' (the beginner of the evil), and the 'tango' will be permitted." [quoted in "Current Opinion," October 1913, as from a letter to the London Times]
tangram (n.): Chinese geometric puzzle, 1864, said to be an arbitrary formation based on anagram, etc. First element perhaps Chinese t'an "to extend," or t'ang, commonly used in Cantonese for "Chinese." Some suggest it is the name of the inventor, "but no such person is known to Chinese scholars" [OED]. Another theory involves the Tanka, an outcast aboriginal people of southern China, and Western sailors who discovered the puzzle from their Tanka girlfriends. Perhaps from an obscure sense of tram. The Chinese name is Ch'i ch'iao t'u "seven ingenious plan."
tangy (adj.): 1875, from tang + -y (2). Figurative use by 1948. Related: Tanginess.
tanist (n.): "elected heir of a Celtic chief," 1530s, from Gaelic tanaiste "presumptive or apparent heir to a lord," literally "parallel, second," from Old Irish tanaise "designated successor," from Celtic *tani-hessio- "one who is waited for."
tank (n.): 1610s, "pool or lake for irrigation or drinking water," a word originally brought by the Portuguese from India, from a Hindi source, such as Gujarati tankh "cistern, underground reservoir for water," Marathi tanken, or tanka "reservoir of water, tank." Perhaps ultimately from Sanskrit tadaga-m "pond, lake pool," and reinforced in later sense of "large artificial container for liquid" (1680s) by Portuguese tanque "reservoir," from estancar "hold back a current of water," from Vulgar Latin *stanticare (see stanch). But other sources say the Portuguese word is the source of the Indian ones. Meaning "fuel container" is recorded from 1902. Slang meaning "detention cell" is from 1912. Railroad tank-car is from 1874.

In military use, "armored, gun-mounted vehicle moving on continuous articulated tracks," the word originated late 1915. In "Tanks in the Great War" [1920], Brevet Col. J.F.C. Fuller quotes a memorandum of the Committee of Imperial Defence dated Dec. 24, 1915, recommending the proposed "caterpillar machine-gun destroyer" machines be entrusted to an organization "which, for secrecy, shall be called the 'Tank Supply Committee,' ..." In a footnote, Fuller writes, "This is the first appearance of the word 'tank' in the history of the machine." He writes that "cistern" and "reservoir" also were put forth as possible cover names, "all of which were applicable to the steel-like structure of the machines in the early stages of manufacture. Because it was less clumsy and monosyllabic, the name 'tank' was decided on." They were first used in action at Pozieres ridge, on the Western Front, Sept. 15, 1916, and the name was quickly picked up by the soldiers. Tank-trap attested from 1920.
tank (v.): 1900, "to put into a tank," from tank (n.). Meaning "to lose or fail" attested from 1976 in a general sense, apparently originally in tennis jargon, specifically in an interview with Billie Jean King in "Life" magazine, Sept. 22, 1967:
"When our men don't feel like trying," she says, "They 'tank' [give up]. I never tanked a match in my life and I never saw a girl do it. The men do it all the time in minor tournaments when they don't feel like hustling. You have to be horribly competitive to win in big-time tennis."
Sometimes said to be from boxing, in some sense, perhaps from the notion of "taking a dive," but evidence for this is wanting. Related: Tanked; tanking. Adjective tanked "drunk" is from 1893.
tank top (n.): 1968, from tank suit "one-piece bathing costume" (1920s), so called because it was worn in a swimming tank (n.), i.e. pool.
tanka (n.): type of Japanese poem, 1877, from Japanese tanka, from tan "short" + ka "song."
tankard (n.): late 14c., "large tub-like vessel," corresponding to Middle Dutch tanckaert, meaning the same thing, but both of unknown origin. A guess hazarded in OED is that it is a transposition of *kantard, from Latin cantharus. Klein suggests French tant quart "as much as a quarter." "The notion that the word is from tank 1 + -ard is wholly untenable" [Century Dictionary]. Meaning "drinking vessel" is first recorded late 15c.
tanker (n.): "ship for carrying oil or other liquid cargo," 1900, from tank (n.).
tanner (n.2): "sixpence," slang word first recorded 1811, of unknown origin. J.C. Hotten, lexicographer of Victorian slang, thinks it may be from tanner and skin, rhyming slang for "thin," presumably in reference to the smallness of the coin. Not to be confused with tenner, slang for "ten-pound note," which dates from 1861.
tanner (n.1): "one who tans leather," Old English tannere, agent noun from tannian (see tan (v.)).
tannery (n.): c. 1400, "process of tanning," from Old French tannerie (13c.) or a native formation from tan (v.) + -ery. Meaning "place where tanning is done" is from 1736, perhaps from tanner (n.1) + -y (2).