ˌsīləˈsībə̇n noun
( -s )
Etymology: International Scientific Vocabulary psilocyb- (from New Latin Psilocybe mexicana , fungus from which it is obtained) + -in ; originally formed in German
: a hallucinogenic indole C 12 H 17 N 2 O 4 P obtained from some fungi (as Psilocybe mexicana )