Green’s Dictionary of Slang

a drug user.

1909		Pharmaceutical Era 41 240/2: The miscellaneous tribes of the pill shop may be included in the following classification of them: boozers, dopers, clock watchers, [etc.].
1916		T. Burke Limehouse Nights 155: He was a dreadful doper. Sometimes he would chew betel nut or bhang or hashish, but mostly it was a big jolt of yen-shi.
1924		Truth (Brisbane) 22 June 12/5: ‘Do more dopers take cocaine than morphine?’.
1925		N. Lucas Autobiog. of a Thief 154: I’m a crook, but, thank God, a clean crook. I’ve no use for dopers.
1934		F. Tuohy Inside Dope 118: Dopers, of both sexes, will tell you what a wonderful aphrodisiac their stuff is.
1940		R. Chandler Farewell, My Lovely (1949) 176: ‘This Dr Sonderberg — what did he look like?’ ‘Like a doper, and probably a dope peddler.’.
1958		R. Chandler Playback 200: You probably knew the night-man was a doper.
1968		N. Heard Howard Street 134: What you bringin’ them dopers up here for, Hip?
1978		A. Maupin Tales of the City (1984) 84: No fats, fems or dopers, please. I’m sincere. Ron.
1989		C. Hiaasen Skin Tight 75: Hoods, dopers, scammers, bikers and stick-up artists.
1992		T. Williams Crackhouse 19: A man from the apartment just below the crackhouse complains loudly [...] and rails about ‘those fucking maricon crack dopers’.
2006		G. Pelecanos Night Gardener 111: Not even a low-ass doper like him [...] should have to live like that.
2010		C. Hiaasen Star Island (2011) 49: It’s not a prison, dude. It’s just a spa for drunks and dopers.