"'Entheogen' is a word coined by scholars proposing to replace the term 'psychedelic' (Ruck, Bigwood, Staples, Ott & Wasson, 1979), which was perceived to be too socioculturally loaded from its 1960s roots to appropriately denote the revered plants and substances used for traditional sacred rituals.What kinds of plants or chemicals fall into the category of entheogen is a matter of debate, as a large number of inebriants - from tobacco and marijuana to alcohol and opium - have been venerated as gifts from the gods (or God) in different cultures at different times (Fuller, 2000). For the purposes of this paper, however, I will focus on the class of drugs that Lewin (1924/1997) terms 'phantastica,' a name deriving from the Greek word for the faculty of the imagination (Shorter Oxford English Dictionary, 1973). Later these substances became known as hallucinogens or psychedelics, a class whose members include lysergic acid derivatives, psilocybin, mescaline and dimethyltryptamine; these all shared physical, chemical, and, when ingested, phenomenological properties and, more importantly, have a history of ritual use as cultural tools to cure illness and/or to mediate cosmological insight (Grinspoon & Bakalar, 1998; Rudgley, 1994, Schultes & Hofmann, 1992;)."
Tupper, Ken, "Entheogens & Education: Exploring the Potential of Psychoactives as Educational Tools," Journal of Drug Education and Awareness, Vol. 1, No. 2, p. 146.