Diabolical means extremely evil or very unpleasant, bad, or annoying. It can describe a plot, scheme, or enemy that is clever and intended for an evil purpose, or a party that is awful and boring. Diabolical means showing the cunning or ingenuity or wickedness typical of a devil, or extremely evil or cruel. Find out the origin, usage, and translations of this adjective, and see related words and antonyms. Morally wrong and evil diabolically (Definition of diabolical from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press) Diabolic and diabolical are two words that are often used interchangeably, but they have slightly different meanings . Diabolic typically refers to something that is evil, wicked, or devilish in nature, while diabolical is often used to describe something that is extremely evil, cruel, or malicious.
