carbonyl group carbonylene • carbonylic · · · Info · Definitions · Characters · · carbonyl group · · Text Common · · Latin · · Scripts 14 · · Length 4 · · Syllables Definitions · · · (noun) the bivalent radical CO. Synonyms: carbonyl group. · · 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 g latin small letter g U+0067 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 u latin small letter u U+0075 y latin small letter y U+0079