two-seater vs automobile

two-seater and automobile both are nouns.

Word	Noun	Adjective	Verb	Adverb
two-seater	Yes	No	No	No
automobile	Yes	No	Yes	No

As nouns, automobile is a hypernym of two-seater; that is, automobile is a word with a broader meaning than two-seater:

two-seater: an open automobile having a front seat and a rumble seat
automobile: a motor vehicle with four wheels; usually propelled by an internal combustion engine

Other hypernyms of two-seater include auto, car, machine, motorcar.

two-seater (noun)	automobile (noun)
an open automobile having a front seat and a rumble seat	a motor vehicle with four wheels; usually propelled by an internal combustion engine

two-seater (verb)	automobile (verb)
	travel in an automobile