window

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An opening constructed in a wall, door, or roof that functions to admit light or air to an enclosure and is often framed and spanned with glass mounted to permit opening and closing.
• noun A framework enclosing a pane of glass for such an opening; a sash.
• noun A pane of glass or similar material enclosed in such a framework.
• noun An opening or transparent part that resembles a window in function or appearance.
• noun The transparent panel on a window envelope.
• noun The area or space immediately behind a window, especially at the front of a shop.
• noun A means of access or observation.
• noun An interval of time during which an activity can or must take place.
• noun Strips of foil dropped from an aircraft to confuse enemy radar; chaff.
• noun A range of electromagnetic frequencies that pass unobstructed through a planetary atmosphere.
• noun Computers A rectangular area on a screen in which a document, database, or application can be viewed independently of the other such areas.
• noun A launch window.
• noun An area at the outer limits of the earth's atmosphere through which a spacecraft must pass in order to return safely.

from The Century Dictionary.

• noun An opening in the wall of a building for the admission of light and air.
• noun An aperture or opening resembling a window or suggestive of a window.
• noun In anatomy, one of two holes in the inner wall of the tympanum, called respectively the oval window and the round window, fenestra ovalis and fenestra rotunda. See fenestra.
• noun A cover; a lid.
• noun A figure formed by lines crossing one another.
• noun A blank space.
• To furnish with a window or with windows.
• To make openings or rents in.
• To place in a window.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To furnish with windows.
• transitive verb rare To place at or in a window.
• noun 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.
• noun (Arch.) The shutter, casement, sash with its fittings, or other framework, which closes a window opening.
• noun rare A figure formed of lines crossing each other.
• noun a period of time in which some activity may be uniquely possible, more easily accomplished, or more likely to succeed.
• noun (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.
• noun (Arch.) a casement window in two folds, usually reaching to the floor; -- called also French casement.
• noun (Arch.) the inside face of the low, and usually thin, piece of wall between the window sill and the floor below.
• noun a blind or shade for a window.
• noun [Scot.] part of a window closed by a shutter which can be opened at will.
• noun one of the hollows in the sides of a window frame for the weights which counterbalance a lifting sash.
• noun the frame of a window which receives and holds the sashes or casement.
• noun panes of glass for windows; the kind of glass used in windows.
• noun (Zoöl.), [Prov. Eng.] the common European martin.
• noun (Zoöl.) 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.
• noun (Arch.), (Zoöl.) See Windowpane, in the Vocabulary.
• noun the sash, or light frame, in which panes of glass are set for windows.
• noun a seat arranged in the recess of a window. See Window stool, under Stool.
• noun a shade or blind for a window; usually, one that is hung on a roller.
• noun (Zoöl.) the window oyster.
• noun a shutter or blind used to close or darken windows.
• noun (Arch.) the flat piece of wood, stone, or the like, at the bottom of a window frame.
• noun (Zoöl.), [Prov. Eng.] the common European martin.