window (opening, usually covered by one or more panes of clear glass, to allow light and air from outside to enter a building)
window (opening, usually covered by glass, in a shop which allows people to view the shop and its products from outside; a shop window)
window (shutter, casement, sash with its fittings, or other framework, which closes a window opening)
window (glass or pane of a window opening)
window (any free place that allows light to pass through and allows one to see something or look inside something)
window (rectangular area on a computer terminal or screen containing some kind of user interface, displaying the output of and allowing input for one of a number of simultaneously running computer processes)
ventilation hole pierced in a coal wall between excavations
opening of an animal's dwelling hole
(obsolete) window (period of time when something is available or possible)
(obsolete) opening in an engine cylinder