black·jack /-ˌʤæk/
 [紙牌] 二十一點


 blackjack
      n 1: a common scrubby deciduous tree of central and southeastern
           United States having dark bark and broad 3-lobed
           (club-shaped) leaves; tends to form dense thickets [syn:
            blackjack oak, jack oak, Quercus marilandica]
      2: a piece of metal covered by leather with a flexible handle;
         used for hitting people [syn: cosh, sap]
      3: a gambling game using cards; the object is to hold cards
         having a higher count than those dealt to the bank up to
         but not exceeding 21 [syn: twenty-one, vingt-et-un]
      v : exert pressure on someone through threats [syn: blackmail,
           pressure]