optical density optical crown glass • optical device · · · Info · Definitions · Synonyms · Characters · · optical density · · Text Common · · Latin · · Scripts 15 · · Length 6 · · Syllables Definitions · · · (noun) (physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation. Synonyms: optical density, transmission density, photographic density, absorbance. · · Noun Definition 1 Synonyms · · · transmission density · · Synonym 1 photographic density · · Synonym 2 absorbance · · Synonym 3 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 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 p latin small letter p U+0070 s latin small letter s U+0073 t latin small letter t U+0074 y latin small letter y U+0079