/ Dictionary / Index M magic mushroom: Meaning and Definition of Find definitions for: mag'ic mush'room Pronunciation: [key] a mushroom, Psilocybe mexicana, of Mexico and the southwestern U.S., containing the hallucinogen psilocybin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Magic Mountain, The* magic number Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language