compact car vs car

compact car and car both are nouns.

Word	Noun	Adjective	Verb	Adverb
compact car	Yes	No	No	No
car	Yes	No	No	No

As nouns, car is a hypernym of compact car; that is, car is a word with a broader meaning than compact car:

compact car: a small and economical car
car: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of compact car include auto, automobile, machine, motorcar.

compact car (noun)	car (noun)
a small and economical car	a motor vehicle with four wheels; usually propelled by an internal combustion engine
	a wheeled vehicle adapted to the rails of railroad
	where passengers ride up and down
	the compartment that is suspended from an airship and that carries personnel and the cargo and the power plant
	a conveyance for passengers or freight on a cable railway