smoker vs stag party

smoker and stag party both are nouns.

Word	Noun	Adjective	Verb	Adverb
smoker	Yes	No	No	No
stag party	Yes	No	No	No

As nouns, smoker and stag party are synonyms defined as:

smoker and stag party: a party for men only (or one considered suitable for men only)

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