Definition of "Psychedelic" :

adjective: (of a mental state) characterized by intense and distorted perceptions and hallucinations and feelings of euphoria or sometimes despair

"A psychedelic experience."

adjective: having the vivid colors and bizarre patterns associated with psychedelic states

"A psychedelic painting."

adjective: producing distorted sensory perceptions and feelings or altered states of awareness or sometimes states resembling psychosis

"Psychedelic drugs like psilocybin and mescaline."