■ noun
1》 an opening in a wall or roof, fitted with glass in a frame to admit light or air and allow people to see out.
↘an opening through which customers are served in a bank, ticket office, etc.
↘a space behind the ~ of a shop where goods are displayed.
↘( a ~ on/into/to ) a means of observing and learning about.
2》 a transparent panel in an envelope to show an address.
3》 Computing a framed area on a display screen for viewing information.
4》 an interval or opportunity for action.
5》 Physics a range of electromagnetic wavelengths for which a medium (especially the atmosphere) is transparent.
6》 strips of metal foil dispersed in the air to obstruct radar detection. [military code word.]
Phrases
go out ( of ) the ~ informal (of a plan or behaviour) be abandoned or cease to exist.
~s of the soul the eyes.
Derivatives
~ed adjective
~less adjective
Origin
ME: from ON vindauga , from vindr 'wind' + auga 'eye'.