station wagon vs auto

station wagon and auto both are nouns.

Word	Noun	Adjective	Verb	Adverb
station wagon	Yes	No	No	No
auto	Yes	No	No	No

As nouns, auto is a hypernym of station wagon; that is, auto is a word with a broader meaning than station wagon:

station wagon: a car that has a long body and rear door with space behind rear seat
auto: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of station wagon include automobile, car, machine, motorcar.

station wagon (noun)	auto (noun)
a car that has a long body and rear door with space behind rear seat	a motor vehicle with four wheels; usually propelled by an internal combustion engine