psilocybin

noun

psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən How to pronounce psilocybin (audio)
: a hallucinogenic indole C12H17N2O4P obtained from a fungus (such as Psilocybe mexicana or P. cubensis synonym Stropharia cubensis)

Examples of psilocybin in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
An undercover officer had bought three batches of seven grams of psilocybin mushrooms and two-gram marijuana vapes from Michael Antonio Kuester between April and June. — Julia Coin updated July 31, Charlotte Observer, 31 July 2026 Taron Ford, 41, was charged with possession with intent to distribute fentanyl, methamphetamine, psilocybin, and marijuana, as well as possession of firearms in furtherance of a drug trafficking crime and being a felon in possession of firearms. — Nathan Pilling july 27, Kansas City Star, 27 July 2026 Regulatory tailwinds are strong, with Compass Pathways nearing FDA submission for psilocybin and Definium Therapeutics reporting robust Phase 3 LSD data. — Robert Glatter, Forbes.com, 20 July 2026 Compass has created a psychedelic drug, COMP360, a synthetic form of psilocybin, that earlier this month scored strong Phase 3 results for treating TRD. — Bob Woods, CNBC, 19 July 2026 See All Example Sentences for psilocybin

Word History

Etymology

New Latin Psilocybe, fungus genus + -in entry 1

First Known Use

1958, in the meaning defined above

Time Traveler
The first known use of psilocybin was in 1958

Browse Nearby Words

psilate
psilocybin
psilomelane
See all Nearby Words

Cite this Entry

“Psilocybin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/psilocybin. Accessed 4 Aug. 2026.

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Kids Definition

psilocybin

noun
psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən How to pronounce psilocybin (audio)
: a chemical that is obtained from a fungus and causes hallucinations

Medical Definition

psilocybin

noun
psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən How to pronounce psilocybin (audio)
: a hallucinogenic indole C12H17N2O4P obtained from a basidiomycetous fungus (as Psilocybe mexicana or P. cubensis synonym Stropharia cubensis)

More from Merriam-Webster on psilocybin

Britannica.com: Encyclopedia article about psilocybin

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