/ Thesaurus / 4 Synonyms of 40 Find synonyms for: Noun1. forty, 40, XL, large integerusage: the cardinal number that is the product of ten and fourAdjective1. forty, 40, xl, twoscore, cardinal (vs. ordinal)usage: being ten more than thirtyWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language