The Collaborative International Dictionary of English v.0.48:

26 \26\ adj.
   1. denoting a quantity consisting of twenty-six items or
      units; -- representing the number twenty-six as Arabic
      numerals

   Syn: twenty-six, xxvi
        [WordNet 1.5 +PJC]

WordNet (r) 3.0 (2006):

26
    adj 1: being six more than twenty [syn: twenty-six, 26,
           xxvi]
    n 1: the cardinal number that is the sum of twenty-five and one
         [syn: twenty-six, 26, XXVI]