diabolical Meaning, Definition & Usage

  1. adjective satellite showing the cunning or ingenuity or wickedness typical of a devil
    mephistophelean; diabolic; devilish; mephistophelian.
    • devilish schemes
    • the cold calculation and diabolic art of some statesmen
    • the diabolical expression on his face
    • a mephistophelian glint in his eye
  2. adjective satellite extremely evil or cruel; expressive of cruelty or befitting hell
    satanic; fiendish; infernal; demonic; hellish; unholy; diabolic.
    • something demonic in him--something that could be cruel
    • fires lit up a diabolic scene
    • diabolical sorcerers under the influence of devils
    • a fiendish despot
    • hellish torture
    • infernal instruments of war
    • satanic cruelty
    • unholy grimaces

WordNet

Di`a*bol"ic, Di`a*bol"ic*al adjective (Also<
  • Diabolic
  • Diabolical
)
Etymology
L. diabolicus, Gr. devilish, slanderous: cf. F. diabolique. See Devil.
Definitions
  1. Pertaining to the devil; resembling, or appropriate, or appropriate to, the devil; devilish; infernal; impious; atrocious; nefarious; outrageously wicked; as, a diabolic or diabolical temper or act. "Diabolic power." Milton. "The diabolical institution." Motley. -- Di`a*bol"ic*al*ly, adv. -- Di`a*bol"ic*al*ness, n.

Webster 1913