psilocybin

noun

psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən 

: 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

This tour also follows Lorde's two years of MDMA and psilocybin therapy, a PTSD treatment, which helped free her from crippling stage fright. —Audrey Gibbs, Nashville Tennessean, 21 Sep. 2025

Denver Post via Getty Images Consumers seeking the therapeutic benefits of psilocybin in Oregon edibles may instead be ingesting unlisted synthetic psychedelics and extracts, a recent study warns. —Benjamin Adams, Forbes.com, 16 Sep. 2025

That would be weird and probably an indication that your microdose of psilocybin had turned into a macrodose. —Brian Moylan, Vulture, 12 Sep. 2025

Afterward, investigators searched a Golden Valley storage unit that Estrada had rented under a false name and seized three bags of white powder, seven bags of psilocybin mushrooms, three bags of marijuana and a bag of meth, according to a search warrant affidavit. —Nick Ferraro, Twin Cities, 11 Sep. 2025

Word History

Etymology

New Latin Psilocybe, fungus genus + -in entry 1

First Known Use

1958, in the meaning defined above

Kids Definition

psilocybin

noun

psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən 

: a chemical that is obtained from a fungus and causes hallucinations

Medical Definition

psilocybin

noun

psi·​lo·​cy·​bin ˌsī-lə-ˈsī-bən 

: a hallucinogenic indole C₁₂H₁₇N₂O₄P obtained from a basidiomycetous fungus (as Psilocybe mexicana or P. cubensis synonym Stropharia cubensis)