orbicularis

noun
or·​bi·​cu·​lar·​is | \ ȯr-ˌbik-yə-ˈler-əs How to pronounce orbicularis (audio) \
plural orbiculares\ -​(ˌ)ēz How to pronounce orbiculares (audio) \

Medical Definition of orbicularis

: a muscle encircling an orifice