pupillary sphincter pupillary reflex • pupilless · · · Info · Definitions · Synonyms · Characters · · pupillary sphincter · · Text Common · · Latin · · Scripts 19 · · Length 6 · · Syllables Definitions · · · (noun) a ring of smooth muscle surrounding the iris. Synonyms: pupillary sphincter, musculus sphincter pupillae. · · Noun Definition 1 Synonyms · · · musculus sphincter pupillae · · Synonym 1 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 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 p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075 y latin small letter y U+0079