A piece of cloth covering a window, bed, etc. to offer privacy and keep out light.

A similar piece of cloth that separates the audience and the stage in a theater.

(theater, by extension) The beginning of a show; the moment the curtain rises.

(fortifications) The flat area of wall which connects two bastions or towers; the main area of a fortified wall.

(euphemistic, also "final curtain", sometimes in the plural) Death.

(architecture) That part of a wall of a building which is between two pavilions, towers, etc.

The uninterrupted stream of fluid that falls onto a moving substrate in the process of curtain coating.

To cover (a window) with a curtain; to hang curtains.

(figurative) To hide, cover or separate as if by a curtain.