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

"A psychedelic experience"

2.Definition: having the vivid colors and bizarre patterns associated with psychedelic states

"A psychedelic painting"

3.Definition: producing distorted sensory perceptions and feelings or altered states of awareness or sometimes states resembling psychosis

"Psychedelic drugs like psilocybin and mescaline"