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

When his oldest son turned 12, Vance admitted to giving his son psilocybin to sell to friends. — Cara Lynn Shultz, PEOPLE, 29 June 2026

The drug showed signs of being clinically effective too, though Yaden is not yet fully sold on the idea that shorter-acting psychedelics can have the same therapeutic pop as a daylong trip on psilocybin. — Ross Andersen, The Atlantic, 12 June 2026

As the patient may have experienced natural fluctuations in her medical condition, the study could not establish that psilocybin directly caused the woman’s improvements. — Melissa Rudy, FOXNews.com, 9 June 2026

Tobacco plants were engineered to produce bufotenine, DMT, psilocin, psilocybin, and 5-MeO-DMT. — Ann Manov, Harpers Magazine, 23 June 2026

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)