[1] : The Collaborative International Dictionary of English v.0.48

xxiv \xxiv\, adj.
   the roman number representing twenty-four.

   syn: twenty-four, 24.
        wordnet 1.5
see also:
twenty-four 

[2] : WordNet (r) 2.0

xxiv
     adj : being four more than twenty syn: twenty-four, 24
     n : the cardinal number that is the sum of twenty-three and one
         syn: twenty-four, 24, two dozen
see also:
twenty-four 24 two dozen 

Xxiv >> X Words
Xxiv, definition of term: Xxiv
xxiv_pag1.html