hypophosphorous acid hypophosphorous • hypophrenia · · · Info · Definitions · Synonyms · Characters · · hypophosphorous acid · · Text Common · · Latin · · Scripts 20 · · Length 7 · · Syllables Definitions · · · (noun) a clear or yellow monobasic acid (H3PO2). Synonyms: hypophosphorous acid, phosphorous acid, orthophosphorous acid. · · Noun Definition 1 Synonyms · · · phosphorous acid · · Synonym 1 orthophosphorous acid · · Synonym 2 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 h latin small letter h U+0068 i latin small letter i U+0069 o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 u latin small letter u U+0075 y latin small letter y U+0079