coach vs railcar

coach and railcar both are nouns.

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

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

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

coach (noun)	railcar (noun)
a carriage pulled by four horses with one driver	a wheeled vehicle adapted to the rails of railroad
a railcar where passengers ride
a vehicle carrying many passengers; used for public transport
a person who gives private instruction (as in singing, acting, etc.)
(sports) someone in charge of training an athlete or a team

coach (verb)	railcar (verb)
teach and supervise (someone); act as a trainer or coach (to), as in sports
drive or operate a coach or carriage