The Collaborative International Dictionary of English v.0.48:
xxvi \xxvi\, adj. The Roman number representing twenty-six. Syn: twenty-six, 26. [WordNet 1.5]WordNet (r) 3.0 (2006):
xxvi 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]