/ Thesaurus / C Synonyms of carbonic acid Find synonyms for: Noun1. carbonic acid, acidusage: a weak acid known only in solution; formed when carbon dioxide combines with waterWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language