complex quantity complex number • complex sentence · · · Info · Definitions · Synonyms · Characters · · complex quantity · · Text Common · · Latin · · Scripts 16 · · Length 6 · · Syllables Definitions · · · (noun) (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1. Synonyms: complex number, complex quantity, imaginary number, imaginary. · · Noun Definition 1 Synonyms · · · complex number · · Synonym 1 imaginary number · · Synonym 2 imaginary · · Synonym 3 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 q latin small letter q U+0071 t latin small letter t U+0074 u latin small letter u U+0075 x latin small letter x U+0078 y latin small letter y U+0079