not to be confused with Shagedelic
The term was first coined as a noun in 1956 by psychiatrist Humphry Osmond, as an alternative descriptor for hallucinogenic drugs in the context of psychedelic psychotherapy. The term featured in a now-famous exchange with Aldous Huxley, in which the ill-fated term phanerothyme was suggested:
To make this trivial world sublime, take half a gram of phanerothyme.
Osmond responded:
To fathom Hell or soar angelic, just take a pinch of psychedelic.
The use of psychedelic drugs became widespread in the mid-1960s. Timothy Leary, who was largely responsible for the popularization of the term "psychedelic", was a well known proponent of their use, as was Aldous Huxley. The fashion for psychedelic drugs gave its name to the visual style of psychedelia, and to a rock music style that became known as psychedelic music.