subcompact car vs motorcar

subcompact car and motorcar both are nouns.

Word	Noun	Adjective	Verb	Adverb
subcompact car	Yes	No	No	No
motorcar	Yes	No	No	No

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

subcompact car: a car smaller than a compact car
motorcar: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of subcompact car include auto, automobile, car, machine.

subcompact car (noun)	motorcar (noun)
a car smaller than a compact car	a motor vehicle with four wheels; usually propelled by an internal combustion engine