1560s, "large carnivorous reptile of the Americas," lagarto, aligarto, a corruption of Spanish el lagarto (de Indias) "the lizard (of the Indies)," from Latin lacertus (see lizard), with Spanish definite article el, from Latin ille (see le).
The modern form of the English word is attested from 1620s, with unetymological -r as in tater, feller, etc. (Alligarter was an early variant) and an overall Latin appearance. The slang meaning "non-playing devotee of swing music" is attested from 1936; the phrase see you later, alligator is from a 1956 song title.
1844, colloquial shortening of alligator.
big spotted cat of the Americas (Felis onca), c. 1600, from Portuguese jaguar, from Tupi jaguara, said in old sources to denote any large beast of prey ["tygers and dogs," in Cullen's translation of Abbe Clavigero's "History of Mexico"]. Compare Tupi jacare "alligator." As a type of stylish British-made car from 1935; in this sense the abbreviation Jag is attested by 1951.
type of tropical American alligator, also cayman, 1570s, from Portuguese or Spanish caiman, from Carib acayouman "crocodile," or perhaps from a Congo African word applied to the reptiles in the new world by African slaves. "The name appears to be one of those like anaconda and bom, boma, which the Portuguese or Spaniards very early caught up in one part of the world, and naturalized in another." [OED]
edible, oily fruit of a tree common in the American tropics, 1763, from Spanish avocado, altered (by folk etymology influence of earlier Spanish avocado "lawyer," from same Latin source as advocate (n.)) from earlier aguacate, from Nahuatl (Aztecan) ahuakatl "avocado" (with a secondary meaning "testicle" probably based on resemblance), from proto-Nahuan *pawa "avocado."
As a color-name, it is attested by 1945. The English corruption alligator (pear) is 1763, from Mexican Spanish alvacata, alligato.
early 14c., "declare to be untrue or untenable," from Old French denoiir "deny, repudiate, withhold," from Latin denegare "to deny, reject, refuse" (source of Italian dinegarre, Spanish denegar), from de "away" (see de-) + negare "refuse, say 'no,' " from Old Latin nec "not," from Italic base *nek- "not," from PIE root *ne- "not."
From late 14c. as "refuse, refuse to grant or give," also "refuse to acknowledge, disavow, disown." Sense of "refuse access to" is from 1660s. Related: Denied; denying.
I may not understand what you say, but I'll defend to your death my right to deny it. [Albert Alligator, "Pogo," Sept. 26, 1951]
"male of a bovine animal," c. 1200, bule, from Old Norse boli "bull, male of the domestic bovine," perhaps also from an Old English *bula, both from Proto-Germanic *bullon- (source also of Middle Dutch bulle, Dutch bul, German Bulle), perhaps from a Germanic verbal stem meaning "to roar," which survives in some German dialects and perhaps in the first element of boulder (q.v.). The other possibility [Watkins] is that the Germanic word is from PIE root *bhel- (2) "to blow, swell."
An uncastrated male, reared for breeding, as opposed to a bullock or steer. Extended after 1610s to males of other large animals (elephant, alligator, whale, etc.). Stock market sense "one who seeks to cause a rise in the price of a stock" is from 1714 (compare bear (n.)). The meaning "policeman" is attested by 1859.
Bull-necked is from 1640s. Figurative phrase take the bull by the horns "boldly face or grapple with some danger or difficulty" is recorded by 1711 (Swift). To be a bull in a china shop, figurative of careless and inappropriately destructive use of force, is attested from 1812 and was the title of a popular humorous song in 1820s England.