- a small opening or perforation, as in a bone, especially between the middle and inner ear.
- a transparent spot in an otherwise opaque surface, as in the wings of certain butterflies and moths.
- a windowlike opening.
- a small opening in or between bones, esp one of the openings between the middle and inner ears
- a transparent marking or spot, as on the wings of moths
- a window or window-like opening in the outside wall of a building
