Breadcrumb Home > Thesaurus > P Synonyms of poison gas Find synonyms for: Noun1. poison gas, gas, chemical weaponusage: a gas that is poisonous to breath or contact; used in chemical warfareWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. ✖ Related Content Daily Word Quiz: perambulate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language