max·il·la 
(măk-sĭlə)
(măk-sĭlə)n. pl. max·il·lae (măk-sĭlē) or max·il·las
1. Anatomy Either of a pair of bones of the human skull fusing in the midline and forming the upper jaw.
2. A homologous bone of the skull in other vertebrates.
3. Either of two laterally moving appendages situated behind the mandibles in insects and most other arthropods.
[Latin, jawbone.]