window

noun

• 1an opening in the wall or roof of a building or vehicle, fitted with glass in a frame to admit light or air and allow people to see out.
• a pane of glass filling a window:thieves smashed a window and took £600
• an opening in a wall or screen through which customers are served in a bank, ticket office, or similar building.
• a space behind the window of a shop where goods are displayed for sale: [as modifier]:beautiful window displays
• a means of observing and learning about something:television is a window on the world

• 2a transparent panel on an envelope to show an address.

• 3 Computing a framed area on a display screen for viewing information.

• 4an interval or opportunity for action:the parliamentary recess offers a good window for a bid
• an interval during which atmospheric and astronomical circumstances are suitable for the launch of a spacecraft.

• 5 Physics a range of electromagnetic wavelengths for which a medium (especially the atmosphere) is transparent.

• 6 [mass noun] strips of metal foil dispersed in the air to obstruct radar detection.

  [military code word]