light second light reflex • light show · · · Info · Definitions · Characters · · light second · · Text Common · · Latin · · Scripts 12 · · Length 3 · · Syllables Definitions · · · (noun) the distance light travels in a vacuum in one second; approximately 300,000 kilometers. Synonyms: light second. · · Noun Definition 1 Characters · · space U+0020 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 g latin small letter g U+0067 h latin small letter h U+0068 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F s latin small letter s U+0073 t latin small letter t U+0074