Source : Webster's Revised Unabridged Dictionary (1913)

Devilry \Dev"il*ry\, n.; pl. {Devilries}.
   1. Conduct suitable to the devil; extreme wickedness;
      deviltry.

            Stark lies and devilry.               --Sir T. More.

   2. The whole body of evil spirits. --Tylor.

Source : WordNet®

devilry
     n 1: wicked and cruel behavior [syn: {deviltry}]
     2: reckless or malicious behavior that causes discomfort or
        annoyance in others [syn: {mischief}, {mischief-making}, {mischievousness},
         {deviltry}, {devilment}, {rascality}, {roguery}, {roguishness},
         {shenanigan}]