prop. a. Pertaining to, or resembling, the devil Mephistopheles, “a crafty, scoffing, relentless fiend;” devilish in character or aspect; crafty; showing cunning or ingenuity or wickedness; as, a mephistophelean glint in his eye. Syn. -- devilish, diabolic, diabolical, mephistophelean. [ 1913 Webster ]
(adj) showing the cunning or ingenuity or wickedness typical of a devil, Syn. diabolic, mephistophelean, mephistophelian, diabolical, Example:devilish schemes; the cold calculation and diabolic art of some statesmen; the diabolical expression on his face; a mephistophelian glint in his eye