sine qua non sine law • sine-qua-nonical · · · Info · Definitions · Synonyms · Characters · · sine qua non · · Text Common · · Latin · · Scripts 12 · · Length Definitions · · · (noun) a prerequisite. Synonyms: essential condition. · · Noun Definition 1 Synonyms · · · sine · · Synonym 1 sin · · Synonym 2 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F q latin small letter q U+0071 s latin small letter s U+0073 u latin small letter u U+0075