ETYM Old Eng. windowe, windoge, Icel. vindauga window, properly, wind eye; akin to Dan. vindue. Related to Wind, and Eye.
In space research, period of time within which a rocket or spacecraft must be launched to accomplish a particular mission; area at the limit of the Earth's atmosphere through which a spacecraft must pass for successful reentry; Computing, section of a vdt screen displaying a particular type of information.
1. An open space in the wall of a building (usually to admit light and air).
2. A framework of wood or metal that contains a glass windowpane and is built into a wall or roof to admit light or air.
3. A transparent opening in a vehicle that allow vision out of the sides or back; usually is capable of being opened.
4. A transparent panel (as of an envelope) inserted in an otherwise opaque material.
5. (Computer science) A rectangular part of a computer screen that contains a display different from the rest of the screen.
6. An opening that resembles a window in appearance or function.

In computer graphics, a defined area in a system not bounded by any limits; unlimited space in graphics.
In applications and graphical interfaces, a portion of the screen that can contain its own document or message. In window-based programs, the screen can be divided into several windows, each of which has its own boundaries and can contain a different document (or another view into the same document).