noun An opening, usually covered by one or more panes of clear glass, to allow light and air from outside to enter a building or vehicle.
She opened the window to let some air in.
noun An opening, usually covered by glass, in a shop which allows people to view the shop and its products from outside; a shop window.
noun The shutter, casement, sash with its fittings, or other framework, which closes a window opening.
noun A period of time when something is available or possible; a limited opportunity.
launch window
noun Something that allows one to see through or into something.
His journal provides a rare window into his otherwise obscure life.
noun A restricted range.
noun A rectangular area on a computer terminal or screen containing some kind of user interface, displaying output and allowing input, often for a single task in a multitasking system.
noun A figure formed of lines crossing each other.