← BackshareGuessdiabolic/ˌdaɪəˈbɑlɪk/adjectiveExtremely evil or cruel; like the devil.The villain in the movie was truly diabolic, showing no mercy to anyone.The dictator's diabolic plan caused the suffering of millions.She gave him a diabolic smile that sent chills down his spine.SynonymsevilwickedsatanicdemonicAntonymsangelicgood