The Collaborative International Dictionary of English v.0.48:
40 \40\ adj. 1. one more than thirty-nine; four times ten; denoting a quantity consisting of fourty items or units; -- representing the number fourty as an Arabic numeral. Syn: forty, xl, twoscore [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
40 adj 1: being ten more than thirty [syn: forty, 40, xl, twoscore] n 1: the cardinal number that is the product of ten and four [syn: forty, 40, XL]