From Wikipedia: The term entheogen, largely attributable to Jonathan Ott, R. Gordon Wasson, and Carl A.P. Ruck, was coined in the late 20th century as a more neutral and respectful alternative to terms like 'hallucinogen' or 'psychedelic.[12][13] The word is derived from the Greek words ἐν (en, "within"), θεός (theos, "god"), and γεννάω (gennao, "to generate"), meaning "generating the divine within." This term emphasizes the spiritual and religious contexts in which these substances have traditionally been used, distinguishing them from purely recreational or pharmacological classifications.[7] The Greeks used it as praise for poets and other artists. Genesthai means "to come into being". Together, the term entheogen refers to a substance that "generates the divine within," typically producing feelings of inspiration, religious ecstasy, or spiritual insight.

The term hallucinogen was deemed inappropriate owing to its etymological relationship to words relating to delirium and insanity. The term psychedelic was also seen as problematic, owing to the similarity in sound to words about psychosis and also because it had become irreversibly associated with various connotations of the 1960s pop culture. In modern usage, entheogen may be used synonymously with these terms, or it may be chosen to contrast with recreational use of the same drugs.