air pump vs ion pump

air pump and ion pump both are nouns.

Word	Noun	Adjective	Verb	Adverb
air pump	Yes	No	No	No
ion pump	Yes	No	No	No

As nouns, ion pump is a hyponym of air pump; that is, ion pump is a word with a more specific, narrower meaning than air pump:

air pump: a pump that moves air in or out of something
ion pump: a vacuum pump that removes gas by ionizing the atoms or molecules and adsorbing them on a metal surface

Other hyponyms of air pump include condensation pump, diffusion pump, inflater, inflator, molecular pump.

air pump (noun)	ion pump (noun)
a pump that moves air in or out of something	a vacuum pump that removes gas by ionizing the atoms or molecules and adsorbing them on a metal surface