/ Dictionary / Index D diabolic: Meaning and Definition of Find definitions for: di•a•bol•ic Pronunciation: (dī"u-bol'ik), [key] — adj. having the qualities of a devil; devilish; fiendish; outrageously wicked: a diabolic plot. pertaining to or actuated by a devil. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diabolic (Thesaurus) diablerie diabolism 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