mid-15c., "short garment for men," from Old French jaquet "short coat with sleeves," diminutive of jaque, a kind of tunic, which is of uncertain origin. Probably it is from Jacque, the male proper name, also the generic name of a French peasant (see jacquerie) with extended material senses as in native jack (n.). But possibly it is from or influenced by jaque (de mailles) "short, tight-fitting coat," originally "coat of mail," from Spanish jaco, from Arabic shakk "breastplate." Meaning "paper wrapper of a book" is first attested 1886.
Iakke, jakke "a short, close-fitting stuffed or quilted tunic, often serving as a defensive garment" is attested in English from late 14c. (from Old French jaque), and by c. 1400 was being used for "woman's short tunic." It is possible that jacket was formed in English as a diminutive of this.
also jack-in-a-box, 1560s, a name for a sharp or cheat, "who deceived tradesmen by substituting empty boxes for others full of money" [Robert Nares, "A Glossary of Words, Phrases, Names, and Allusions," London, 1905]. See Jack + box (n.1). As a type of toy involving a figure on a spring inside a box, it is attested by 1702. Also it has been used variously to mean "peddler who sells wares from a temporary stall" (1690s), "an unborn child," a type of gambling game, a hermit crab, a large wooden male screw, the sacrament, and various mechanical devices.
also jackknife, "pocket knife larger than a pen-knife," 1711, probably American English, apparently from some sense of jack (n.). Perhaps it originally was associated with sailors. Jackleg, jacklegged was a U.S. colloquial term of contempt from 1839. Scottish dialect had jockteleg (1670s) "large clasp-knife," of unknown origin, also jackylegs, jack-o-legs. As a kind of swimming dive from 1922; as a type of tractor-trailer accident, 1966; both from the notion of folding, as the knife does.
1776, "to stab," from jack-knife (n.). Intransitive meaning "to fold or bend" the body is said to date from the time of the American Civil War. The truck accident verbal sense is from 1949. Related: Jackknifed; jackknifing.
also jack-o-lantern, jack-a-lantern, jackolantern, 1660s, "night-watchman;" 1670s as a local name for a will-o-the-wisp (Latin ignis fatuus), mainly attested in East Anglia but also in southwestern England. Literally "Jack of (with) the lantern;" see Jack + lantern. The extension to carved pumpkin lanterns is attested by 1834 in American English.
also jack-pot, "big prize," 1944, from slot machine sense (1932), from now-obsolete poker sense (1881) in reference to antes that begin when no player has a pair of jacks or better; from jack (n.) in the card-playing sense + pot (n.1). Earlier, in criminal slang, it meant "trouble," especially "an arrest" (1902).
The regular Draw-Poker game is usually varied by occasional Jack-Pots, which are played once in so many deals, or when all have refused to play, or when the player deals who holds the buck, a marker placed in the pool with every jack-pot. In a jack-pot each player puts up an equal stake and receives a hand. The pot must then be opened by a player holding a hand of the value of a pair of knaves (jacks) or better. If no player holds so valuable a hand the deal passes and each player adds a small sum to the pot or pool. When the pot is opened the opener does so by putting up any sum he chooses, within the limit, and his companions must pay in the same amount or "drop." They also possess the right to raise the opener. The new cards called for are then dealt and the opener starts the betting, the play proceeding as in the regular game. [ Encyclopaedia Britannica, 11th ed., 1911, "Poker." The article notes "Jack-Pots were introduced about 1870."]
To hit the jackpot "be very successful" is from 1938.
type of terrier (not recognized as a distinct breed), 1907, named for the Rev. John Russell (1795-1883) of Devonshire, "the sporting parson."
