hydroxyl hydroxyketone • hydroxylactone · · · Info · Definitions · Synonyms · Characters · · hydroxyl · · Text Latin · · Script 8 · · Length 3 · · Syllables Definitions · · · (noun) the monovalent group -OH in such compounds as bases and some acids and alcohols. Synonyms: hydroxyl group, hydroxyl radical. · · Noun Definition 1 Synonyms · · · hydroxyl group · · Synonym 1 hydroxyl radical · · Synonym 2 Characters · · d latin small letter d U+0064 h latin small letter h U+0068 l latin small letter l U+006C o latin small letter o U+006F r latin small letter r U+0072 x latin small letter x U+0078 y latin small letter y U+0079