sport car vs motorcar

sport car and motorcar both are nouns.

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

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

sport car: a small low car with a high-powered engine; usually seats two persons
motorcar: a motor vehicle with four wheels; usually propelled by an internal combustion engine

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

sport car (noun)	motorcar (noun)
a small low car with a high-powered engine; usually seats two persons	a motor vehicle with four wheels; usually propelled by an internal combustion engine