a person who smokes tobacco
"After years of living with him, she finally kicked her habit and quit being a smoker."
a party for men only (or one considered suitable for men only)
"The invitation explicitly stated that the annual smoker was reserved exclusively for male guests."
a passenger car for passengers who wish to smoke
"The old train had a dedicated smoker's car at the back where travelers could light up without bothering their neighbors."
A person who smokes tobacco habitually.
"After years of being a smoker, Mark finally quit to protect his health."
A surname.
"The local history club recently welcomed Mr. Smoker, whose family has lived in the valley for over three centuries."