Green’s Dictionary of Slang

cokie n.

also coakie, cokey
[coke n.1 , on pattern of junkie n.]

1. [1910s+] (drugs) a habitual user of cocaine; thus [1930s–50s] Cokie Joe, a personification of a regular cocaine user.

2. [1910s+] (drugs, also coke) a habitual user of heroin or opium.

3. [1920s–60s] (US Und.) any form of drug addict.

4. [1940s] (US gang) a boy, usu. derog., esp. when referring to a member of another gang.