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

Three other states, Colorado, New Mexico and Oregon, have legalized psilocybin mushrooms for therapeutic use. —Esme Murphy, CBS News, 11 Apr. 2026

Even for people living outside those states and cities, the barriers to accessing psilocybin mushrooms are low. —Hollis Karoly, The Conversation, 9 Apr. 2026

Both Ali and Katz underlined that psilocybin is not a magic cure-all. —Natalia V. Osipova, CNN Money, 28 Mar. 2026

Registration prices include psilocybin mushrooms, which are served in capsules and tea or on their own. —Tiney Ricciardi, Denver Post, 18 Mar. 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)