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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

Etymology

Origin of psychedelic

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

Explanation

Psychedelic originally described drugs — especially LSD — that made users experience bizarre, mind-bending sounds and images, real and imagined. Soon psychedelic was also used for music, art, and colors that seemed to fit a drug-induced haze. Psychedelic art is wild, vivid, and might make you a little dizzy, like an electric pink tie-dyed t-shirt or a scene of phosphorescent green poodles in high heels, hiking the Alps against a purple-plaid sky. Psychedelic rock is heavy on electronic sounds and intricate instrumentation, in the style the Grateful Dead, Jimi Hendrix, and the Beatles’ Sgt. Peppers album. The word, dating from the 1950s, comes from the Greek psyche, “soul, mind” and delos “clear” — just what psychedelic isn’t.

Keep Reading on Vocabulary.com

Vocabulary lists containing psychedelic

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.

"But especially in the psychedelic field, completely new scaffolds are incredibly rare. And this is the discovery of a brand-new therapeutic scaffold."

From Science Daily • May 14, 2026

Five days ago, Trump signed an executive order intended to boost access to psychedelic drugs for medical treatment.

From BBC • Apr. 23, 2026

However, the pomp and circumstance of the signing, as well as the limited material consequences of the order has left those working for psychedelic reform divided on how to think about it.

From Salon • Apr. 22, 2026

President Donald Trump signs a directive to accelerate FDA review of psychedelic drugs for serious mental illness.

From Barron's • Apr. 20, 2026

Its roof lights flash red and blue on the water, creating a psychedelic sheen.

From "Enrique's Journey" by Sonia Nazario

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