Trademark. (used with a singular verb)

any of several personal computer operating systems or environments featuring a graphical user interface.




an opening in the wall of a building, the side of a vehicle, etc., for the admission of air or light, or both, commonly fitted with a frame in which are set movable sashes containing panes of glass.
such an opening with the frame, sashes, and panes of glass, or any other device, by which it is closed.
the frame, sashes, and panes of glass, or the like, intended to fit such an opening: Finally the builders put in the windows.
a windowpane.
anything likened to a window in appearance or function, as a transparent section in an envelope, displaying the address.
a period of time regarded as highly favorable for initiating or completing something: Investors have a window of perhaps six months before interest rates rise.
Military. chaff1(def 5).
Geology. fenster.
Pharmacology. the drug dosage range that results in a therapeutic effect, a lower dose being insufficient and a higher dose being toxic.
  1. launch window.
  2. a specific area at the outer limits of the earth's atmosphere through which a spacecraft must reenter to arrive safely at its planned destination.
Computers. a section of a display screen that can be created for viewing information from another part of a file or from another file: The split screen feature enables a user to create two or more windows.

verb (used with object)

to furnish with a window or windows.
Obsolete. to display or put in a window.

Origin of window

1175–1225; Middle English windoge, windowe < Old Norse vindauga, equivalent to vindr wind1 + auga eye

Related formswin·dow·less, adjectivewin·dow·y, adjectiveun·win·dowed, adjectivewell-win·dowed, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for windows

British Dictionary definitions for windows



a light framework, made of timber, metal, or plastic, that contains glass or glazed opening frames and is placed in a wall or roof to let in light or air or to see throughRelated adjective: fenestral
an opening in the wall or roof of a building that is provided to let in light or air or to see through
the display space in and directly behind a shop windowthe dress in the window
any opening or structure resembling a window in function or appearance, such as the transparent area of an envelope revealing an address within
an opportunity to see or understand something usually unseena window on the workings of Parliament
a period of unbooked time in a diary, schedule, etc
physics a region of the spectrum in which a medium transmits electromagnetic radiationSee also radio window
computing an area of a VDU display that may be manipulated separately from the rest of the display area; typically different files can be displayed simultaneously in different overlapping windows
(modifier) of or relating to a window or windowsa window ledge
out of the window informal dispensed with; disregarded


(tr) to furnish with or as if with windows

Word Origin for window

C13: from Old Norse vindauga, from vindr wind 1 + auga eye 1

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for windows



early 13c., literally "wind eye," from Old Norse vindauga, from vindr "wind" (see wind (n.1)) + auga "eye. (see eye (n.)). Replaced Old English eagþyrl, literally "eye-hole," and eagduru, literally "eye-door."

Originally an unglazed hole in a roof, most Germanic languages adopted a version of Latin fenestra to describe the glass version, and English used fenester as a parallel word till mid-16c. Window dressing is first recorded 1790; figurative sense is from 1898. Window seat is attested from 1778. Window-shopping is recorded from 1922. Window of opportunity (1979) is from earlier figurative use in U.S. space program, e.g. launch window (1965).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for windows




A fenestra.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with windows


see out the window.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.