Air pump

1. A pump used to exhaust from a condenser the condensed steam, the water used for condensing, and any commingled air.
2. 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.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.