smoker vs smoking car

smoker and smoking car both are nouns.

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

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

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

Other synonyms of smoker include smoking carriage, smoking compartment.

smoker (noun)	smoking car (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