The phrase "air pump" refers to a device that is used to move or pump air, either to inflate something like a tire or to circulate air in a closed space. Full definition
This is the best portable air pump for car tires for anyone on a budget. (geekwrapped.com)
The system included an electric air pump which was connected to the on - board power supply via the cigarette lighter. (mercedes-benz.com)
Included with this stroller is a tiny portable air pump so that you can always be sure that the tired are full and ready to go. (earlymomentsmatter.org)