Definition of window glass in US English:

window glass

noun

  • 1The pane of glass in a window.

  • 2As a mass noun: glass used for windowpanes.

adjective

  • Usually hyphenated. Designating a pair of spectacles with pieces of normal glass in place of lenses, for wearing, e.g., as part of a costume or as a fashion accessory.

Origin

Late 16th century; earliest use found in Philip Sidney (1554–1586), author and courtier. From window + glass.