smoking car vs coach

smoking car and coach both are nouns.

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

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

Other hypernyms of smoking car include carriage, passenger car.

smoking car (noun)	coach (noun)
a passenger car for passengers who wish to smoke	a carriage pulled by four horses with one driver
	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

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