optical opacity optical maser • optical phenomenon · · · Info · Definitions · Characters · · optical opacity · · Text Common · · Latin · · Scripts 15 · · Length 7 · · Syllables Definitions · · · (noun) opacity to light. Synonyms: optical opacity. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 i latin small letter i U+0069 l latin small letter l U+006C o latin small letter o U+006F p latin small letter p U+0070 t latin small letter t U+0074 y latin small letter y U+0079