PUMP

noun

1. A device for moving or compressing a liquid or gas.
2. An instance of the action of a pump; one stroke of a pump; any action similar to pumping
3. A device for dispensing liquid or gas to be sold, particularly fuel.

verb

1. To use a pump to move (liquid or gas).
2. (often followed by up) To fill with air.
3. To move rhythmically, as the motion of a pump.