coach vs smoking car

coach and smoking car both are nouns.

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

As nouns, smoking car is a hyponym of coach; that is, smoking car is a word with a more specific, narrower meaning than coach:

coach (noun)	smoking car (noun)
a carriage pulled by four horses with one driver	a passenger car for passengers who wish to smoke
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)	smoking car (verb)
teach and supervise (someone); act as a trainer or coach (to), as in sports
drive or operate a coach or carriage