carbonic acid carbonic • carbonic acid gas · · · Info · Definitions · Characters · · carbonic acid · · Text Common · · Latin · · Scripts 13 · · Length 5 · · Syllables Definitions · · · (noun) a weak acid known only in solution; formed when carbon dioxide combines with water. Synonyms: carbonic acid. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 d latin small letter d U+0064 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072