Definition of "Blackjack" :

noun: 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

noun: a flag usually bearing a white skull and crossbones on a black background; indicates a pirate ship

noun: a piece of metal covered by leather with a flexible handle; used for hitting people

noun: 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

verb: exert pressure on someone through threats