mandible

Short definition from Wiktionary

Noun

1. 1
   The jaw or a jawbone, especially the lower jawbone in mammals and fishes.
2. 2
   Either of the upper and lower segments of a bird's beak.
3. 3
   Any of various invertebrate mouthparts serving to hold or bite food materials.
4. 4
   Any of various invertebrate mouthparts serving to hold or bite food materials: One of the anterior pair of mouthparts of an arthropod, designed for holding and cutting food.