An envelope with a transparent panel on its front, through which the name and address of the addressee printed on the letter inside can be seen.

A window that opens and closes by sliding a pane, as opposed to folding in or out. / (programming) A descriptor for a data analysis technique where overlapping windows of data of fixed size are analyzed.

A period of time, often in which a task is to be done

A window of time of increased anabolic activity.

Alternative form of broken windows theory

plural of window stool

(architecture) A horizontal board, usually made of wood, on a windowsill, fitted against the bottom rail of the lower sash.

(architecture) A large semicircular window, characteristic of the enormous public baths (thermae) of Ancient Rome.