In medicine, to create one or more openings in a tissue: Dr. Smart showed his students how to fenestrate the soft substances they were working on.

1. In anatomy, perforated by one or more openings: The tissues Dr. Blacks showed his students were all fenestrated with holes of different sizes. 2. Made with windows or similar openings in a building: When Mr. and Mrs. White had their house built for them, they were happy to have so many big fenestrated walls, and even one fenestrated part in the roof!
3. Regarding something that has openings or perforations: The woolen coat that Mrs. Green had, had so many fenestrated spots where some moths had eaten away!
4. A description of a lepidopteran's wings that have transparent markings: Sam enjoyed looking at the beautiful butterfly with fenestrated wings.

A very thin layer of body tissue that covers something with one or more openings (fenestrae), as found in large arteries: The fenestrated membrane is a very thin anatomical structure that has minute window-like openings or pores,

A protective covering with a window cut in the tip or lateral convexity (surface that is evenly curved outward), through which special cutting instruments can be passed: A resectoscope rmust have a fenestrated sheath when is used in cavities, like an an prostate operation through the urethra.