digastric muscle

n.

1. A muscle with two fleshy bellies separated by a fibrous insertion.
2. A muscle consisting of two bellies united by a central tendon connected to the body of the hyoid bone, with origin from the digastric groove medial to the mastoid process, with insertion into the lower border of the mandible, with nerve supply of the posterior belly from the facial nerve, and of the anterior belly by the mylohyoid nerve, and whose action elevates the hyoid when the mandible is fixed and depresses the mandible when the hyoid is fixed.