"Reefer" Natural Recordings by Native Speakers
A reefer typically refers to:
1. A refrigerator: a machine for cooling and preserving food by the use of refrigeration.
2. A person who smokes marijuana, often using a marijuana cigarette: a slang term that originated from the resemblance of marijuana joints to a short, hand-rolled cigar, often used in informal contexts.
Informal context:
The term is derived from the fact that marijuana cigarettes were often sold in small brown paper packages, resembling a reefer shipment (sea freight).
Note: The second definition is considered informal.