blackjack
1. black.jack \'blak-.jak\ n [black + jack (vessel)] 1: a tankard for beer or ale usu. of tar-coated leather 2: SPHALERITE 3: a hand weapon typically consisting of a piece of leather-enclosed metal with a strap or springy shaft for a handle 4: a common often scrubby oak (Quercus marilandica) of the southeaste rn and southern U.S. with black bark 5: TWENTY-ONE 2. blackjack vt : to strike with or as if with a blackjack