n. pl. fe·nes·trae (-trē′)
1. Anatomy A small anatomical opening, as in a bone.
2. An opening in a bone made by surgical fenestration.
3. Zoology A transparent spot or marking, as on the wing of a moth or butterfly.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.