win·dow 
/ˈwɪndoʊ/ noun
plural win·dows /ˈwɪndoʊ/ noun 1 [count] a : an opening in a wall, door, etc., that usually contains a sheet of glass
▪ She opened a window to let in some air. ▪ I looked out the window and saw a deer. — see also bay window, french window, picture window, rose window, storm window
b : a sheet of glass that covers an opening in a building, vehicle, etc.
▪ He used vinegar and water to wash the windows. ▪ He accidentally broke a window. ▪ Can you roll down the car window?
c : a large window at the front of a store where goods are displayed so that they can be seen by people who are walking past
▪ The windows along 5th Avenue were all decorated for Christmas. ▪ I saw a beautiful dress in the window.
d : an opening in a wall through which business is conducted
▪ He sits behind a window and sells movie tickets. ▪ a ticket window ▪ a bank teller's window 2 [count] : a part of something that you can see through
▪ Make sure the address shows through the window in the envelope. ▪ A window opened in the fog and we could finally see the ocean. 3 [count] : an area or box on a computer screen that shows a program that is currently running
▪ Minimize that window and open a new one. ▪ Close all the windows and restart the computer. — see picture at computer 4 [singular] : a period of time during which something can happen
▪ The shuttle's launch has a window of only two days. [=it can only happen within two specific days] ▪ The window of opportunity [=the time during which there is a chance to do something] has closed/ended.
▪ She opened a window to let in some air. ▪ I looked out the window and saw a deer. — see also bay window, french window, picture window, rose window, storm window
b : a sheet of glass that covers an opening in a building, vehicle, etc.
▪ He used vinegar and water to wash the windows. ▪ He accidentally broke a window. ▪ Can you roll down the car window?
c : a large window at the front of a store where goods are displayed so that they can be seen by people who are walking past
▪ The windows along 5th Avenue were all decorated for Christmas. ▪ I saw a beautiful dress in the window.
d : an opening in a wall through which business is conducted
▪ He sits behind a window and sells movie tickets. ▪ a ticket window ▪ a bank teller's window
▪ Make sure the address shows through the window in the envelope. ▪ A window opened in the fog and we could finally see the ocean.
▪ Minimize that window and open a new one. ▪ Close all the windows and restart the computer. — see picture at computer
▪ The shuttle's launch has a window of only two days. [=it can only happen within two specific days] ▪ The window of opportunity [=the time during which there is a chance to do something] has closed/ended.
a window into/on
: something that makes it possible to see or understand something clearly
▪ This knowledge opens a window into your opponent's mind. ▪ The book gives the reader a window on war.
▪ This knowledge opens a window into your opponent's mind. ▪ The book gives the reader a window on war.
go out the window
informal : to stop being used or thought about
▪ By that point in the argument, reason had gone out the window.
▪ By that point in the argument, reason had gone out the window.
throw (something) out the window
informal : to stop using or thinking about (something)
▪ We can throw that idea out the window.
▪ We can throw that idea out the window.
