/ Thesaurus / W Synonyms of water vapor Find synonyms for: Noun1. water vapor, water vapour, vapor, vapourusage: water in a vaporous form diffused in the atmosphere but below boiling temperatureWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language