XX

from WordNet (r) 3.0 (2006)

xx
    adj 1: denoting a quantity consisting of 20 items or units [syn:
           {twenty}, {20}, {xx}]
    n 1: the cardinal number that is the sum of nineteen and one
         [syn: {twenty}, {20}, {XX}]
    2: (genetics) normal complement of sex chromosomes in a female

from The Collaborative International Dictionary of English v.0.48

xx \xx\, adj.
   The Roman number representing {twenty}; denoting a quantity
   consisting of 20 items or units.

   Syn: twenty, 20, score.
        [WordNet 1.5]