The Collaborative International Dictionary of English v.0.48:
Window \Win"dow\, v. t. [imp. & p. p. Windowed; p. pr. & vb.
1. To furnish with windows.
2. To place at or in a window. [R.]
Wouldst thou be windowed in great Rome and see
Thy master thus with pleach'd arms, bending down
His corrigible neck? --Shak.
The Free On-line Dictionary of Computing (30 December 2018):
Software which allows a computer's
display to be divided into rectangular areas which act like a
separate input/output devices under the control of different
application programs. This gives the user the ability to see
the output of several processes at once and to choose which one
will receive input by selecting its window, usually by pointing at
it with a mouse.
Examples are the X Window System, proprietary systems on the
Macintosh and NeXT, NeWS on Suns, RISC OS on the
Archimedes and Microsoft Windows. See also WIMP.