carriage vs railcar

carriage and railcar both are nouns.

Word	Noun	Adjective	Verb	Adverb
carriage	Yes	No	No	No
railcar	Yes	No	No	No

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

Other hypernyms of carriage include car, railroad car, railway car.

carriage (noun)	railcar (noun)
a vehicle with wheels drawn by one or more horses	a wheeled vehicle adapted to the rails of railroad
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