ski tow vs chair lift

ski tow and chair lift both are nouns.

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

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

ski tow: 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 tow include chairlift, rope tow, surface lift.

ski tow (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