Air'-pŭmp, n.

noun

n. 1. A pump or machine, variously constructed, for exhausting the air from a closed vessel.

Sense 2. (Steam-engines.) A pump used to exhaust from a condenser the condensed steam, the water used for condensing, and the air that has come out of this water when warmed by the condensation of steam.

An antique air pump with a large cylindrical chamber and a hand-operated mechanism mounted on a wooden base.
Air-pump.