/ Dictionary / Index H hallucinogen: Meaning and Definition of Find definitions for: hal•lu•ci•no•gen Pronunciation: (hu-l'su-nu-jun), [key] — n. a substance that produces hallucinations. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hallucinogen (Thesaurus) hallucinatory hallucinogenic Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language