say it: REE-fur
reefer is a noun meaning "marijuana leaves rolled into a cigarette for smoking". It carries one recorded sense.
marijuana leaves rolled into a cigarette for smoking
Forms marked are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for reefer come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.