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

Colorado's first license for a psilocybin healing center was given to The Center Origin in downtown Denver. —Axios Denver, Axios, 1 Apr. 2025

One element was, if anyone takes psilocybin mushrooms, there’s always a feeling of another presence there, or something watching you. —Roxana Hadadi, Vulture, 31 Mar. 2025

In 2023, the Legislature passed a bill to decriminalize the personal use of psilocybin mushrooms and other psychedelics. —Grant Stringer, The Mercury News, 25 Mar. 2025

Adverse effects of psilocybin, including headache and nausea, typically resolve within one to two days. —Kate Ruder | Kff Health News, ABC News, 24 Mar. 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)