cantus firmus cantus • cantwise · · · Info · Definitions · Characters · · cantus firmus · · Text Common · · Latin · · Scripts 13 · · Length 4 · · Syllables Definitions · · · (noun) a melody used as the basis for a polyphonic composition. Synonyms: cantus firmus. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 f latin small letter f U+0066 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075