nonsmoking car vs carriage

nonsmoking car and carriage both are nouns.

Word	Noun	Adjective	Verb	Adverb
nonsmoking car	Yes	No	No	No
carriage	Yes	No	No	No

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

nonsmoking car: a passenger car for passengers who want to avoid tobacco smoke
carriage: a railcar where passengers ride

Other hypernyms of nonsmoking car include coach, passenger car.

nonsmoking car (noun)	carriage (noun)
a passenger car for passengers who want to avoid tobacco smoke	a vehicle with wheels drawn by one or more horses
	a railcar where passengers ride
	a machine part that carries something else
	a small vehicle with four wheels in which a baby or child is pushed around
	characteristic way of bearing one's body