temporalis

noun

tem·​po·​ral·​is ˌtem-pə-ˈrā-ˌləs 

: a large muscle in the temporal fossa that serves to raise the lower jaw and is composed of fibers that arise from the surface of the temporal fossa and converge to an aponeurosis which contracts into a thick flat tendon inserted into the coronoid process of the mandible

called also temporalis muscle, temporal muscle