/ Dictionary / Index D demoniac: Meaning and Definition of Find definitions for: de•mo•ni•ac Pronunciation: (di-mō'nē-ak", dē"mu-nī'ak), [key] — adj. of, pertaining to, or like a demon; demonic: demoniac laughter. possessed by or as by an evil spirit; raging; frantic. —n. a person seemingly possessed by a demon or evil spirit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: demoniac (Thesaurus) demonetize demonian Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language