smoking car vs carriage

smoking car and carriage both are nouns.

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

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

Other hypernyms of smoking car include coach, passenger car.

smoking car (noun)	carriage (noun)
a passenger car for passengers who wish to 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