Medical Dictionary

sphincter pupillae

noun sphincter pu·pil·lae \-pyü-ˈpil-ē\

Medical Definition of SPHINCTER PUPILLAE

:  a broad flat band of smooth muscle in the iris that surrounds the pupil of the eye

Browse

How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears