English Reference
adjective · noun

psychedelic

adj. · n.
US /ˌsaɪkəˈdɛɫɪk/ UK /sˌaɪkɪdˈɛlɪk/ psy·che·del·ic

  1. 01 C1 Advanced Technical Medicine

    adj.describing drugs or experiences that change how you see, hear, and feel reality.

    adj.relating to or denoting drugs that produce hallucinations and apparent expansion of consciousness.

    Simple

    The scientist studied the psychedelic effects of certain mushrooms on the brain.

    In context

    Research into psychedelic compounds has seen a resurgence as clinicians explore their potential for treating treatment-resistant depression and anxiety.

    hallucinogenicmind altering
  2. 02 B2 Upper Intermediate

    adj.having bright colors, strange patterns, and abstract shapes like those in 1960s art.

    adj.characterized by bold colors and distorted or abstract patterns reminiscent of drug-induced hallucinations.

    Simple

    The band played in front of a psychedelic background of swirling purple and green lights.

    In context

    The graphic designer utilized a psychedelic palette to evoke the counterculture aesthetic of the late 1960s for the festival poster.

    trippymulticoloredvivid
  3. 03 C1 Advanced Technical Medicine

    n.a drug that causes hallucinations and changes how you think.

    n.a psychoactive substance, such as LSD or psilocybin, that produces distortions of perception and altered awareness.

    Simple

    He spoke about his experiences taking psychedelics during his youth.

    In context

    The legal status of various psychedelics is currently being debated in several jurisdictions following promising results in clinical trials.

    hallucinogen

Participants also showed brain connectivity patterns resembling those associated with psychedelic experiences, suggesting that powerful altered states may be achievable without drugs.

ScienceDaily· 9 Aug 2026

Psychedelics, the study hints, could offer a new option for addressing one of psychiatry’s most difficult-to-treat conditions.

Smithsonian Magazine· 11 Aug 2026

From Ancient Greek ψυχή (psukhḗ, “mind, soul”) + δῆλος (dêlos, “manifest, visible”) + English -ic (prefix forming adjectives with the sense ‘of or pertaining to’), coined by the English psychiatrist Humphry Osmond (1917–2004) in a 1956 letter to Aldous Huxley.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Ancient Greek ψυχή
Level C1 · Advanced
Frequency Frequent
Updated