/ Dictionary / Index C carbonic acid: Meaning and Definition of Find definitions for: carbon'ic ac'id Pronunciation: [key] the acid, HCO, formed when carbon dioxide dissolves in water, known in the form of its salts and esters, the carbonates. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. carbonic carbonic-acid gas Related Content Daily Word Quiz: penurious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language