police cruiser vs auto

police cruiser and auto both are nouns.

Word	Noun	Adjective	Verb	Adverb
police cruiser	Yes	No	No	No
auto	Yes	No	No	No

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

police cruiser: a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters
auto: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of police cruiser include automobile, car, machine, motorcar.

police cruiser (noun)	auto (noun)
a car in which policemen cruise the streets; equipped with radiotelephonic communications to headquarters	a motor vehicle with four wheels; usually propelled by an internal combustion engine