luminous flux luminous energy • luminous flux unit · · · Info · Definitions · Characters · · luminous flux · · Text Common · · Latin · · Scripts 13 · · Length 4 · · Syllables Definitions · · · (noun) the rate of flow of light energy. Synonyms: luminous flux. · · Noun Definition 1 Characters · · space U+0020 f latin small letter f U+0066 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 s latin small letter s U+0073 u latin small letter u U+0075 x latin small letter x U+0078