1. an opening in a wall or roof fitted with glass to admit light or air
2. a transparent panel in a vehicle
3. a period of time when something is possible or available

1. to provide with windows

Examples

• She opened the window to let in fresh air.
• The car window was rolled down.
• There’s a narrow window of opportunity to apply.
• I opened a new window in my browser.
• The architect windowed the entire south wall.
• Rain streaked down the bedroom window.
• The launch window closes at midnight.