smoking compartment vs smoker

smoking compartment and smoker both are nouns.

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

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

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

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

smoking compartment (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