Definition of blackjack
1 a
: a card game the object of which is to be dealt cards having a higher count than those of the dealer up to but not exceeding 21 — called also
twenty-one, vingt-et-un
b
: an ace and a face card or ten as the first two cards dealt to a player in the game of blackjack — called also
natural, twenty-one
2
: a hand weapon typically consisting of a piece of leather-enclosed metal with a strap or springy shaft for a handle
3
[black + jack (vessel)]
: a tankard for beer or ale usually of tar-coated leather
4
: sphalerite
5
: an often scrubby oak (Quercus marilandica) chiefly of the southeastern U.S. — called also
blackjack oak
