ski lift vs chair lift

ski lift and chair lift both are nouns.

Word	Noun	Adjective	Verb	Adverb
ski lift	Yes	No	No	No
chair lift	Yes	No	No	No

As nouns, chair lift is a hyponym of ski lift; that is, chair lift is a word with a more specific, narrower meaning than ski lift:

ski lift: a powered conveyance that carries skiers up a hill
chair lift: a ski lift on which riders (skiers or sightseers) are seated and carried up or down a mountainside; seats are hung from an endless overhead cable

Other hyponyms of ski lift include chairlift, rope tow, surface lift.

ski lift (noun)	chair lift (noun)
a powered conveyance that carries skiers up a hill	a ski lift on which riders (skiers or sightseers) are seated and carried up or down a mountainside; seats are hung from an endless overhead cable