Meaning : Showing the cunning or ingenuity or wickedness typical of a devil.
Example :
Devilish schemes.
The cold calculation and diabolic art of some statesmen.
The diabolical expression on his face.
A mephistophelian glint in his eye.
Synonyms : diabolic, diabolical, mephistophelean, mephistophelian
Meaning : In a playfully devilish manner.
Example :
The socialists are further handicapped if they believe that capitalists are not only wicked but also devilishly clever.
Synonyms : devilishly