The word joint ultimately originated from French, where it is an adjective meaning "joined" (past participle of the verb joindre), derived in turn from Latin iunctus, past participle of iungere ("join"/"bind"/"yoke").
By 1821, "joint" had become an Anglo-Irish term for an annexe, or a side-room "joined" to a main room. By 1877, this had developed into U.S. slang for a (usually unsavory) "place, building, establishment," especially referring to an opium den. By 1935, "joint" was being used to refer to the hypodermic needles used to inject heroin and other drugs at such establishments; this may have been influenced by the secondary meaning of "joint" in the sense of something done "in common" or shared. Its first usage in the sense of "marijuana cigarette" is dated to 1938.