The Collaborative International Dictionary of English v.0.48:

Devilry \Dev"il*ry\, n.; pl. Devilries.
   1. Conduct suitable to the devil; extreme wickedness;
      deviltry.
      [1913 Webster]

            Stark lies and devilry.               --Sir T. More.
      [1913 Webster]

   2. The whole body of evil spirits. --Tylor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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

Moby Thesaurus II by Grady Ward, 1.0:

83 Moby Thesaurus words for "devilry":
   Black Mass, Satanism, arrantness, badness, baseness, bitchiness,
   black magic, chthonian worship, cruelty, cussedness, demonism,
   demonography, demonolatry, demonology, demonomancy, demonomy,
   demonry, devil lore, devil worship, devilishness, devilment,
   deviltry, diablerie, diabolism, diabology, diabolology, elfishness,
   evil, evil intent, evilness, fiendishness, flagitiousness,
   foolishness, foulness, harmfulness, hatefulness, heinousness,
   hellishness, high spirits, impishness, iniquitousness, iniquity,
   invidiousness, knavery, knavishness, maleficence, malevolence,
   malice, malice aforethought, malice prepense, maliciousness,
   malignance, malignancy, malignity, meanness, mischief,
   mischievousness, nastiness, naughtiness, nefariousness,
   noxiousness, orneriness, perversity, playfulness, prankishness,
   pranksomeness, puckishness, rankness, rascality, roguery,
   roguishness, scampishness, sinfulness, sorcery, sportiveness,
   viciousness, vileness, villainousness, villainy, waggery,
   waggishness, wickedness, youthful spirits