Noun, pl. fenestras or fenestrae
1. A term is used to refer to a natural (as opposed to traumatic) opening in the skull or other bones. (wikipedia.org)
2. An opening in a body, sometimes with a membrane. (wiktionary.org)
3. A small natural hole or opening, esp. in a bone. The mammalian middle ear is linked by the fenestra ovalis to the vestibule of the inner ear, and by the fenestra rotunda to the cochlea. (Google Dictionary)
4. An artificial opening. (Google Dictionary)
5. A perforation in a forceps blade. (Google Dictionary)
6. A hole made by surgical fenestration. (Google Dictionary)
Word origin: A Latin word that means “window”.