smok ‧ er /ˈsməʊkə $ ˈsmoʊkər/ BrE AmE noun [countable]
[ Word Family: noun : ↑ smoke , ↑ smoker ≠ ↑ non-smoker , ↑ smoking , ↑ smokiness ; adjective : ↑ smoked , smoking ≠ ↑ non-smoking , ↑ smoky , ↑ smokeless ; verb : ↑ smoke ]
someone who smokes cigarettes, ↑ cigar s etc OPP non-smoker :
My grandad was a heavy smoker (=someone who smokes a lot) .
He had a smoker’s cough (=a cough caused by smoking cigarettes regularly) .