Reefer
1930s: perhaps related to Mexican Spanish grifo ‘(smoker of) cannabis’.
wiktionary
From reef + -er.
Clipping of refrigerator.
Origin uncertain. Perhaps from Mexican Spanish grifa(“cannabis”) or Central American Spanish grifo(“someone who smokes cannabis”).
etymonline
reefer (n.)
"marijuana cigarette," 1920s, perhaps an alteration of Mexican Spanish grifo "marijuana, drug addict" [OED]; or perhaps from reef (v.), on resemblance to a rolled sail. It also meant "pickpocket" in criminal slang (by 1935), and Century Dictionary also has it as "oyster that grows on reefs in the wild."
Reefer also was a nickname for the sailing navy's equivalent to a midshipman (1818) "because they attend in the tops during the operation of reefing" [Century Dictionary], which is the source of the meaning "coat of a nautical cut" (1878) worn by sailors and fishermen "but copied for general use in the fashions of 1888-90" [CD].
