Mandible

Webster's Dictionary of the English Language

·noun The bone, or principal bone, of the lower jaw; the inferior maxilla;

— also applied to either the upper or the lower jaw in the beak of birds.

II. Mandible ·noun The anterior pair of mouth organs of insects, crustaceaus, and related animals, whether adapted for biting or not. ·see ·Illust. of Diptera.