dining car vs carriage

dining car and carriage both are nouns.

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

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

Other hypernyms of dining car include coach, passenger car.

dining car (noun)	carriage (noun)
a passenger car where food is served in transit	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