fe·nes·tra 
(fə-nĕstrə)
(fə-nĕstrə)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.
[Latin, window.]
fe·nestral adj.