1. an opening in the wall of a building, the side of a vehicle, etc., for the admission of air or light, or both, commonly fitted with a frame in which are set movable sashes containing panes of glass.
2. such an opening with the frame, sashes, and panes of glass, or any other device, by which it is closed.
Origin:
1175–1225; ME windoge, windowe < ON vindauga, equiv. to vindr wind 1 + auga eye