pane

An individual sheet of glass in a window, door, etc.

We need doubling glazing as this window pane lets out lots of heat.

A portion of a user interface that typically makes up part of a larger window and may be docked or snapped into position.

A division; a distinct piece or compartment of any surface.

A square of a checkered or plaid pattern.

One of the openings in a slashed garment, showing the bright colored silk, or the like, within; hence, the piece of colored or other stuff so shown.

To fit with panes.

For example, by paning the glass horizontally (putting a single horizontal slat through the middle of the window), it almost looks as if you installed two windows.

Alternative spelling of peen.