maxilla

maxilla (noun; plural maxillae; Latin maxilla, jaw): 1. (Annelida: Polychaeta) The large, hook-shaped, dorsal chitinous jaw plate.

2. (Arthropoda) In most arthropods, one of the paired mouth-part structures posterior to the mandibles or jaws; third pair of head appendages.

3. (Arthropoda: Diplopoda) One of the paired second jaws to form the gnathochilarium.