MDDa cigarette containing the drug marijuana 大麻香烟SYN joint
Examples from the Corpus
reefer• Renate was sitting on the edge of the king-sized bed with the black sheets, smoking a reefer.• Top Shop is doing a brisk trade in reefer jackets and A-line car coats.• Another source of inspiration was the naval reefer jacket of the late nineteenth century.
Originreefer
(1900-2000) Perhaps from → REEF2 (in the sense “to roll something up”), or perhaps from Mexican Spanishgrifo“(someone who smokes) marijuana”