definition of
blackjack

[1] #1 blackjack n. [blackjack oak, jack oak, Quercus marilandica] a common scrubby deciduous tree of central and southeastern United States having dark bark and broad three-lobed (club-shaped) leaves; tends to form dense thickets. wn

[2] #2 blackjack v. [blackmail, pressure] exert pressure on someone through threats. wn

[3] #3 blackjack n. [cosh, sap] a piece of metal covered by leather with a flexible handle; used for hitting people. wn

[4] #4 blackjack n. [black flag, pirate flag, Jolly Roger] a flag usually bearing a white skull and crossbones on a black background; indicates a pirate ship. wn

[5] #5 blackjack n. [twenty-one, vingt-et-un] a gambling game using cards; the object is to hold cards having a higher count than those dealt to the banker up to but not exceeding 21. wn