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.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.