smoking car vs smoker

smoking car and smoker both are nouns.

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

As nouns, smoking car and smoker are synonyms defined as:

smoking car and smoker: a passenger car for passengers who wish to smoke

Other synonyms of smoking car include smoking carriage, smoking compartment.

smoking car (noun)	smoker (noun)
a passenger car for passengers who wish to smoke	a passenger car for passengers who wish to smoke
	a party for men only (or one considered suitable for men only)
	a person who smokes tobacco