From The Collaborative International Dictionary of English v.0.48 [gcide]:
30 \30\ adj.
1. one more than twenty-nine; three times ten; denoting a
quantity consisting of thirty items or units; --
representing the number thirty as an Arabic numeral.
Syn: thirty, xxx
[WordNet 1.5 +PJC]
From WordNet (r) 3.0 (2006) [wn]:
30
adj 1: being ten more than twenty [syn: thirty, 30, xxx]
n 1: the cardinal number that is the product of ten and three
[syn: thirty, 30, XXX]