rə̇ˈsōrēəs, rīˈ-, -ˈzō- noun
( plural riso·rii -ēˌī)
Etymology: New Latin, from Latin risus (past participle of ridēre to laugh) + -orius -ory — more at ridiculous
: a narrow band of muscle fibers arising from the fascia over the masseter muscle and inserted into the tissues at the corner of the mouth