Defn: See Jack-with-a-lantern, under 2d Jack. JACKPOT
Jackpot
Defn: 1. (a) See "jack pot" under jack; (b) any larger-than-usual gambling prize formed by the accumulation of unwon bets[=MW10 1(a)(2) and 1(c)]; (c) the highest gambling prize awarded in a gambling game in which smaller prizes are also awarded, especially such a prize on a slot machine.
Defn: 2. (a) An unusually large success in an enterprise, either unexpected or unpredictable, esp. one providing a great financial benefit. hit the jackpotto receive an unexpectedly large (or the largest possible) benefit from an enterprise.
JACKPUDDING
Jack"pud`ding, n.
Defn: A merry-andrew; a buffoon. Milton.
JACKSAW
Jack"saw`, n. (Zoöl.)
Defn: The merganser.
JACKSCREW
Jack"screw`, n.
Defn: A jack in which a screw is used for lifting, or exerting pressure. See Illust. of 2d Jack, n., 5.
JACKSLAVE
Jack"slave`, n.