1. [syn: air pump, vacuum pump]
The Collaborative International Dictionary of English v.0.48:
Air pump \Air" pump`\
1. (Physics) A kind of pump for exhausting air from a vessel
or closed space; also, a pump to condense air or force it
into a closed space.
2. (Steam Engines) A pump used to exhaust from a condenser
the condensed steam, the water used for condensing, and
any commingled air.
WordNet (r) 3.0 (2006):
n 1: a pump that moves air in or out of something [syn: air
pump, vacuum pump]