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psychedelic

American  
[sahy-ki-del-ik] / ˌsaɪ kɪˈdɛl ɪk /
Sometimes psychodelic

adjective

  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.

  3. characterized by images, sounds, or feelings resembling those experienced while in the altered state produced by psychedelic drugs: The psychedelic designs of music posters in the 60s were inspired by the Art Nouveau movement of the late 1800s.

    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.


noun

  1. a psychedelic drug.

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

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

psychedelic British  
/ ˌsaɪkɪˈdɛlɪk /

adjective

  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

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

"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

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


Discover More

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

Other Word Forms

  • prepsychedelic adjective
  • psychedelically adverb

Etymology

Origin of psychedelic

First recorded in 1956; from psyche + Greek dêl(os) “visible, manifest, evident” + -ic

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

His sound expanded with 2014’s “Metamodern Sounds in Country Music,” which incorporated psychedelic arrangements into songs that mused on philosophy and the nature of the universe.

From The Wall Street Journal • Mar. 17, 2026

East L.A.’s Tropa Magica led the crowd into another dimension with their psychedelic cumbias, periodicallyhowling at the moon during their rock jam session.

From Los Angeles Times • Mar. 16, 2026

"Our findings are consistent with a growing scientific perspective suggesting that psychedelic effects and serotonergic activity may be dissociated," says Andrea Mattarei, a corresponding author of the study.

From Science Daily • Mar. 8, 2026

Part of the beauty and profundity of people’s psychedelic experiences is the ineffable—but the systems that run on Western science are hungry for hard data, replicable and reliable outcomes, and, perhaps most importantly, profit.

From Slate • Jan. 30, 2026

Geometric and psychedelic shapes, mosaics, and mandalas...There is a calm in the chaos that most folks don’t see.

From "Monday's Not Coming" by Tiffany D. Jackson