n.
1.a framework of wood or metal that contains a glass windowpane and is built into a wall or roof to admit light or air
2.a transparent opening in a vehicle that allow vision out of the sides or back
3.a transparent panel (as of an envelope) inserted in an otherwise opaque material
4.an opening that resembles a window in appearance or function
5.the time period that is considered best for starting or finishing something
6.a pane in a window
7.an opening in the wall of a building (usually to admit light and air)
8.(computer science) a rectangular part of a computer screen that contains a display different from the rest of the screen