fen·es·tra·tion noun \ˌfen-ə-ˈstrā-shən\
a : a natural or surgically created opening in a surface b : the presence of such openings
: the operation of cutting an opening in the bony labyrinth between the inner ear and tympanum to replace natural fenestrae that are not functional
Seen & Heard
What made you want to look up fenestration? Please tell us where you read or heard it (including the quote, if possible).