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.

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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

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psychedelic Cultural  

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

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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

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.

Example Sentences

Dave Mason, a founding member of the British psychedelic rock band Traffic who wrote some of their best-known songs including “Feelin’ Alright?” and “Hole in My Shoe,” has died.

From Los Angeles Times • Apr. 22, 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

As developments in the Middle East remained in focus over the weekend, President Donald Trump quietly signed a directive hastening the review of certain psychedelic drugs.

From Barron's • Apr. 20, 2026

The stocks of several companies developing psychedelic treatments for mental illnesses soared in premarket trade on Monday morning after President Donald Trump put his support behind them.

From MarketWatch • Apr. 20, 2026

Argus rolled his eyes in disgust, which looked pretty psychedelic since it made his whole body swirl.

From "The Last Olympian" by Rick Riordan

Related Words

• hallucinatory
• kaleidoscopic
• multicolored