air spring vs cushion

air spring and cushion both are nouns.

Word	Noun	Adjective	Verb	Adverb
air spring	Yes	No	No	No
cushion	Yes	No	Yes	No

As nouns, cushion is a hypernym of air spring; that is, cushion is a word with a broader meaning than air spring:

air spring: a mechanical device using confined air to absorb the shock of motion
cushion: a mechanical damper; absorbs energy of sudden impulses

Other hypernyms of air spring include shock, shock absorber.

air spring (noun)	cushion (noun)
a mechanical device using confined air to absorb the shock of motion	a soft bag filled with air or a mass of padding such as feathers or foam rubber etc.
	a mechanical damper; absorbs energy of sudden impulses
	the layer of air that supports a hovercraft or similar vehicle

air spring (verb)	cushion (verb)
	protect from impact