- c.1225, lit. "wind eye," from O.N. vindauga, from vindr "wind" (see wind (n.)) + auga "eye."
- Replaced O.E. eagþyrl, lit. "eye-hole," and eagduru, lit. "eye-door."
- Originally an unglazed hole in a roof, most Gmc. languages adopted a version of L. fenestra to describe the glass version, and Eng. used fenester as a parallel word till mid-16c.
- Window dressing is first recorded 1790; fig. sense is from 1898. Window seat is attested from 1778. Window-shopping is recorded from 1922. Window of opportunity (1979) is from earlier fig. use in U.S. space program, e.g. launch window (1965).
――Online Etymology Dictionary