The Collaborative International Dictionary of English v.0.48:
ix \ix\ adj. The Roman numerals signifying nine; denoting a quantity consisting of one more than eight and one less than ten. Syn: nine, 9. [WordNet 1.5]WordNet (r) 3.0 (2006):
ix adj 1: denoting a quantity consisting of one more than eight and one less than ten [syn: nine, 9, ix] n 1: the cardinal number that is the sum of eight and one [syn: nine, 9, IX, niner, Nina from Carolina, ennead]