fenestration

plural fenestrations

1. countableuncountablearchitectureThe arrangement of windows and similar openings in a building.
2. countableuncountableanatomyAn 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. countableuncountableanatomyAn opening that occurs naturally or is created surgically, as through a biological membrane.
4. countableuncountablebiologyEither a translucent area in a structure such as a leaf or flower petal, or an opening in a structure.

   Foliar traits unique to Darlingtonia include the presence of transparent light-transmitting fenestrations, ...

   2016 D. W. Armitage, Systematic Botany 103(4):780–785. p. 781

   1 more example

   The terms ‘nectar window’ and ‘fenestration’ are used interchangeably for enlarged gaps on the adaxial side of the stamen sheath or tube. The fenestrations facilitate access to the nectaries by a pollinator.

   2005, S. Tucker, Australian Systematic Botany, 19(3):193-210. p. 194

5. countableuncountablenauticalThe practice of placing holes in the rudder of a ship to reduce the work required to move the rudder while preserving its ability to steer the ship.