twen·ty-one /ˌtwɛntiˈwʌn, ˌtwʌn-/
  no.二十一
  twenty-one
       adj : being one more than twenty [syn: 21, xxi]
       n 1: the cardinal number that is the sum of twenty and one [syn:
            21, XXI]
       2: 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: blackjack, vingt-et-un]