Simple Definition of hallucinogen

from our Learner's Dictionary

hallucinogen

noun

həˈluːsənəʤən How to pronounce hallucinogen (audio)
plural hallucinogens
: a substance (such as a drug) that causes people to see or sense things that are not real : a substance that causes hallucinations

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“Hallucinogen.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/hallucinogen. Accessed 17 Apr. 2026.

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More from Merriam-Webster on hallucinogen

Nglish: Translation of hallucinogen for Spanish Speakers

Britannica.com: Encyclopedia article about hallucinogen

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