Psycheelic drugs are psychoactive drugs whose primary action is to alter the thought processes of the brain and perception of the mind. The term is derived from Greek ψυχή (psyche, "mind") and δηλείν (delein, "to manifest"), translating to "mind-manifesting." "The implication is that the psychedelic drugs can develop unused potentials of the human mind." Psychedelic drugs are part of a wider class sometimes known as the hallucinogens, which also includes related substances such as dissociatives and deliriants. Unlike other psychoactive drugs such as stimulants and opioids, the psychedelics do not merely induce familiar states of mind but rather shift the focus of experiences so that they are qualitatively different from those of ordinary consciousness. The psychedelic experience is often compared to non-ordinary forms of consciousness such as trance, meditation, and dreams.