orbicularis oris UK /ɔːˌbɪk.jʊˌlɑː.ɹɪs ˈɒ.ɹɪs/US /ɔɹˌbɪk.jəˌlɛɹ.ɪs ˈɔɹ.ɪs/ noun1 •A muscle made up of several layers of fibers passing in different directions that surrounds the mouth and controls most movements of the lips (as compressing, closing, or pursing movements). formsorbiculares orum
