[ sahy-ki-del-ik ]
See synonyms for psychedelic on
  1. of or noting a mental state characterized by a profound sense of intensified sensory perception, sometimes accompanied by severe perceptual distortion and hallucinations and by extreme feelings of either euphoria or despair: LSD users seek the psychedelic properties of the drug, including heightened sensory experiences.

  2. of, relating to, or noting any of various drugs producing this state, such as LSD, mescaline, or psilocybin: Researchers have long been interested in the potential therapeutic effects of psychedelic drugs for humans.

  1. characterized by images, sounds, or feelings resembling those experienced while in the altered state produced by psychedelic drugs: Their music had a dreamy psychedelic sound, with gentle guitars and hushed vocals.The psychedelic designs of music posters in the 60s were inspired by the Art Nouveau movement of the late 1800s.

  1. a psychedelic drug: The clinic will start treating patients with ketamine, a psychedelic.

  2. Rare. a person who uses such a substance.

Origin of psychedelic

First recorded in 1956; from psyche + Greek dêl(os) “visible, manifest, evident” + -ic
  • Sometimes psy·cho·del·ic [sahy-kuh-del-ik] /ˌsaɪ kəˈdɛl ɪk/ .

Other words from psychedelic

  • psy·che·del·i·cal·ly, adverb
  • pre·psych·e·del·ic, adjective

Words Nearby psychedelic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use psychedelic in a sentence

British Dictionary definitions for psychedelic



/ (ˌsaɪkɪˈdɛlɪk) /

  1. relating to or denoting new or altered perceptions or sensory experiences, as through the use of hallucinogenic drugs

  2. denoting any of the drugs, esp LSD, that produce these effects

  1. informal (of painting, fabric design, etc) having the vivid colours and complex patterns popularly associated with the visual effects of psychedelic states

Origin of psychedelic

C20: from psyche + Greek delos visible

Derived forms of psychedelic

  • psychedelically or psychodelically, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Cultural definitions for psychedelic


[ (seye-kuh-del-ik) ]

A descriptive term for things that produce or are related to hallucinations, especially drugs such as LSD.

Notes for psychedelic

Psychedelic art, most popular during the late 1960s and early 1970s, combines patterns, objects, light, and sound to simulate hallucinatory experiences.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.