window

noun

• 1an opening in the wall or roof of a building or vehicle that is fitted with glass or other transparent material 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 on the inside of a store’s window where goods are displayed for sale:I prefer the red dress that’s in the window [as modifier]:beautiful window displays

• 2a thing resembling a window in form or function, in particular.
• a transparent panel on an envelope to show an address.
• Computing a framed area on a display screen for viewing information.
• (window on/into/to) a means of observing and learning about:television is a window on the world
• Physics a range of electromagnetic wavelengths for which a medium (especially the atmosphere) is transparent.

• 3an interval or opportunity for action:February 15 to March 15 should be the final window for new offers
• an interval during which atmospheric and astronomical circumstances are suitable for the launch of a spacecraft.

• 4strips of metal foil or metal filings dispersed in the air to obstruct radar detection.

  [military code word]