fenestration

noun

1. The arrangement of windows and similar openings in a building.
2. An opening in the surface of an organ etc; the surgical creation of such an opening, especially one in the bony part of the inner ear made to improve hearing.
3. An opening that occurs naturally or is created surgically, as through a biological membrane.
4. Either a translucent area in a structure such as a leaf or flower petal, or an opening in a structure.