(science fiction) A person who works or lives in space.

An object inserted to hold a space open in a row of items, e.g. beads or printed type.

A bushing.

(slang) A forgetful person; one who spaces out.

(medicine) A type of add-on device used by an asthmatic person to increase the effectiveness of a metered-dose inhaler.

(historical) An instrument for reversing a telegraphic current, especially in a marine cable, to increase the speed of transmission.