- a short, leather-covered club, consisting of a heavy head on a flexible handle, used as a weapon.
- black flag(defs 1, 2).
- a small oak, Quercus marilandica, of the eastern U.S., having a nearly black bark and a wood of little value except for fuel.
- a large drinking cup or jug for beer, ale, etc., originally made of leather coated externally with tar.Compare bombard(def 7).
- caramel or burnt sugar for coloring spirits, vinegar, coffee, etc.
- Mineralogy. a dark, iron-rich variety of sphalerite.
verb (used with object)
- to strike or beat with a blackjack.
- to compel by threat.
- John JosephBlackjack, 1860–1948, U.S. general: commander of the American Expeditionary Forces in World War I.
- a 46-ton (42 metric tons) U.S. heavy tank of 1944–52, with a five-man crew and a 90mm gun.
- a two-stage surface-to-surface ballistic missile.
- a truncheon of leather-covered lead with a flexible shaft
- (tr) to hit with or as if with a blackjack
- (tr) to compel (a person) by threats
- pontoon or any of various similar card games
- the ace of spades
- a dark iron-rich variety of the mineral sphalerite
- a small oak tree, Quercus marilandica, of the southeastern US, with blackish bark and fan-shaped leavesAlso called: blackjack oak
- a tarred leather tankard or jug
- John Joseph, nickname Black Jack. 1860–1948, US general. He was commander in chief of the American Expeditionary Force in Europe (1917–19)
- a US ballistic missile capable of carrying a nuclear or conventional warhead
used in many senses since 16c., earliest is possibly “tar-coated leather jug for beer” (1590s), from black (adj.) + jack in any of its many slang senses. The weapon so called from 1889; the card game by 1900.