Merriam-Webster Collegiate Dictionary - maxilla

 noun  (plural ~e or ~s)  Etymology: Latin, diminutive of mala jaw  Date: 1676  1.  a. jaw 1a  b.  (1) an upper jaw especially of humans and other mammals in which the bony elements are closely fused  (2) either of the two bones that lie with one on each side of the upper jaw lateral to the pre~ and that in higher vertebrates bear most of the teeth  2. one of the first or second pair of mouthparts posterior to the mandibles in many arthropods (as insects or crustaceans)  • ~ry adjective or noun