chain smoker
A person who smokes cigarettes continuously, such that they begin a new cigarette as (or almost as) soon as the last one is extinguished. My grandmother died of emphysema after being a chain smoker for most of her adult life.
chain smoker
One who smokes continually by lighting a new cigarette from the one being finished, as in Before they forbade smoking, bridge tournaments often attracted players who are chain smokers . [c. 1930]
chain-smoker
n. someone who smokes cigarette after cigarette. She was a chain-smoker for thirty years, and then suddenly, boom. She’s gone.