smoker vs smoking compartment

smoker and smoking compartment both are nouns.

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

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

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

Other synonyms of smoker include smoking car, smoking carriage.

smoker (noun)	smoking compartment (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