window

The word “window” means an opening in a wall, usually fitted with glass, that lets in light and air. In plain terms, a glass opening in a wall, a limited timeframe for doing something, or a screen panel in software.

“Window” is pronounced WIHN-doh (/ˈwɪndoʊ/ in IPA).

Here is “window” used in a sentence: “She opened the window to let in some fresh air.”

Words with a similar meaning to “window” include glass.

“Window” is a noun.

The word “window” comes from Old Norse. From Old Norse vindauga, literally "wind-eye" — an opening that let wind (and light) into a building, before glass panes were common.

“Window” is a very common word in modern English, usually learned at around the A1 level.

“Window” has 3 distinct senses listed in this dictionary. The most common is: an opening in a wall, usually fitted with glass, that lets in light and air.

Common styles include casement windows, hinged at the side; sash windows, which slide up and down; sliding windows, which move sideways; bay and bow windows, which project outward; and fixed or picture windows that do not open. Each balances light, ventilation, and appearance differently to suit the building.

A window is an opening set in a wall, letting in light and air from the side. A skylight is a window fitted into a roof or ceiling, bringing light from above. Both use glass, but their position differs: windows look outward, while skylights look up to the sky.

Windows let in natural light and fresh air, reducing the need for artificial lighting and improving ventilation. They offer views, connect indoor spaces to the outside, and affect a building's warmth, energy use, and mood. Well-placed windows can make rooms feel larger, brighter, and more comfortable to occupy.

Yes. Beyond the opening in a wall, window can mean a period of opportunity, as in a launch window or a window of time; a framed area on a computer screen; or a transparent panel in an envelope. Each borrows the idea of an opening you can see or act through.