The Collaborative International Dictionary of English v.0.48:

Window \Win"dow\, n. [OE. windowe, windoge, Icel. vindauga
   window, properly, wind eye; akin to Dan. vindue. ????. See
   Wind, n., and Eye.]
   [1913 Webster]
   1. An opening in the wall of a building for the admission of
      light and air, usually closed by casements or sashes
      containing some transparent material, as glass, and
      capable of being opened and shut at pleasure.
      [1913 Webster]

            I leaped from the window of the citadel. --Shak.
      [1913 Webster]

            Then to come, in spite of sorrow,
            And at my window bid good morrow.     --Milton.
      [1913 Webster]

   2. (Arch.) The shutter, casement, sash with its fittings, or
      other framework, which closes a window opening.
      [1913 Webster]

   3. A figure formed of lines crossing each other. [R.]
      [1913 Webster]

            Till he has windows on his bread and butter. --King.
      [1913 Webster]

   4. a period of time in which some activity may be uniquely
      possible, more easily accomplished, or more likely to
      succeed; as, a launch window for a mission to Mars.
      [PJC]

   5. (Computers) a region on a computer display screen which
      represents a separate computational process, controlled
      more or less independently from the remaining part of the
      screen, and having widely varying functions, from simply
      displaying information to comprising a separate conceptual
      screen in which output can be visualized, input can be
      controlled, program dialogs may be accomplished, and a
      program may be controlled independently of any other
      processes occurring in the computer. The window may have a
      fixed location and size, or (as in modern Graphical User
      Interfaces) may have its size and location on the screen
      under the control of the operator.
      [PJC]
      [1913 Webster]

   French window (Arch.), a casement window in two folds,
      usually reaching to the floor; -- called also French
      casement.

   Window back (Arch.), the inside face of the low, and
      usually thin, piece of wall between the window sill and
      the floor below.

   Window blind, a blind or shade for a window.

   Window bole, part of a window closed by a shutter which can
      be opened at will. [Scot.]

   Window box, one of the hollows in the sides of a window
      frame for the weights which counterbalance a lifting sash.


   Window frame, the frame of a window which receives and
      holds the sashes or casement.

   Window glass, panes of glass for windows; the kind of glass
      used in windows.

   Window martin (Zool.), the common European martin. [Prov.
      Eng.]

   Window oyster (Zool.), a marine bivalve shell (Placuna
      placenta) native of the East Indies and China. Its valves
      are very broad, thin, and translucent, and are said to
      have been used formerly in place of glass.

   Window pane.
      (a) (Arch.) See Pane, n., 3
      (b) .
      (b) (Zool.) See Windowpane, in the Vocabulary.

   Window sash, the sash, or light frame, in which panes of
      glass are set for windows.

   Window seat, a seat arranged in the recess of a window. See
      Window stool, under Stool.

   Window shade, a shade or blind for a window; usually, one
      that is hung on a roller.

   Window shell (Zool.), the window oyster.

   Window shutter, a shutter or blind used to close or darken
      windows.

   Window sill (Arch.), the flat piece of wood, stone, or the
      like, at the bottom of a window frame.

   Window swallow (Zool.), the common European martin. [Prov.
      Eng.]

   Window tax, a tax or duty formerly levied on all windows,
      or openings for light, above the number of eight in houses
      standing in cities or towns. [Eng.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Windowpane \Win"dow*pane`\, n.
   1. (Arch.) See Pane, n., (3)
      b . [In this sense, written also window pane.]
        [1913 Webster]

   2. (Zool.) A thin, spotted American turbot (Pleuronectes
      maculatus) remarkable for its translucency. It is not
      valued as a food fish. Called also spotted turbot,
      daylight, spotted sand flounder, and water flounder.
      [1913 Webster]

WordNet (r) 3.0 (2006):

window pane
    n 1: street name for lysergic acid diethylamide [syn: acid,
         back breaker, battery-acid, dose, dot, Elvis,
         loony toons, Lucy in the sky with diamonds, pane,
         superman, window pane, Zen]