Source : Webster's Revised Unabridged Dictionary (1913)

Devilment \Dev"il*ment\, n.
   Deviltry. --Bp. Warburton.

Source : WordNet®

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