window

Etymology

From Middle English windowe, from Old Norse vindauga (“window”, literally “wind eye”), equivalent to wind + eye. Cognate with Scots windae and windock, Faroese vindeyga, Norwegian vindu, Danish vindue, archaic Swedish vindöga, Elfdalian windog and older German Windauge. Displaced native Old English ēagþȳrel (literally “eye hole”). The “windows” among early Germanic peoples were just unglazed holes (eyes) in the wall or roof that permitted wind to pass through .

noun

1. An opening, usually covered by one or more panes of clear glass, to allow light and air from outside to enter a building or vehicle.
   A window is an opening in a wall to admit light and air. 1952, L. F. Salzman, Building in England, page 173
   Nanny Broome was looking up at the outer wall. Just under the ceiling there were three lunette windows, heavily barred and blacked out in the normal way by centuries of grime. 1963, Margery Allingham, chapter 14, in The China Governess
2. An opening, usually covered by glass, in a shop which allows people to view the shop and its products from outside; a shop window.
3. (architecture) The shutter, casement, sash with its fittings, or other framework, which closes a window opening.
4. A period of time when something is available or possible; a limited opportunity.
   launch window;  window of opportunity;  You have a two-hour window of clear weather to finish working on the lawn.
   But rescuers have a dwindling window of opportunity, with forecasters predicting the return of heavy monsoon rains in the coming days, effectively sealing off the cave until October. 2018-07-08, Euan McKirdy, Hilary Whiteman, “Thai cave rescue: Divers enter cave to free boys”, in edition.cnn.com, CNN, retrieved 2018-07-08
   Now she'll be thinking about fleeing. (The verdict delay) provides a window for potential flight....if she has not fled already. 2017-08-25, Euan McKirdy et al., “Arrest warrant to be issued for former Thai PM Yingluck Shinawatra”, in edition.cnn.com, CNN, retrieved 2017-08-25
   An extensive period of trial running will then take place in the first quarter of 2020. The full opening of the Elizabeth Line is still planned to be within a six-month window between October 2020 and March 2021. November 6 2019, “Network News”, in Rail, page 26
5. Something that allows one to see through or into something
   His journal provides a window into his otherwise obscure life.
6. A restricted range.
   In this case, a band-pass filter using a range or window of frequencies is appropriate to isolate the frequency or the group of frequencies that characterize a specific cycle. 2015, Patrick R. Nicolas, Scala for Machine Learning, page 109
7. (graphical user interface) A rectangular area on a computer terminal or screen containing some kind of user interface, displaying the output of and allowing input for one of a number of simultaneously running computer processes.
8. A figure formed of lines crossing each other.
   till he has windows on his bread and butter 1709, William King, Art of Cookery
9. (medicine) The time between first infection and detectability.
10. (military, historical, uncountable) Synonym of chaff (“strips of material intended to confuse radar”)
11. (signal processing) A function multiplied with a signal to reduce spectral leakage when performing a Fourier transform.

verb

1. (transitive) To furnish with windows.
2. (transitive) To place at or in a window.
3. (transitive, signal processing) To apply a window function to (a signal).