Pit"i*less*ness

from The Collaborative International Dictionary of English v.0.48

Pitiless \Pit"i*less\, a.
   1. Destitute of pity; hard-hearted; merciless; as, a
      pitilessmaster; pitiless elements.
      [1913 Webster]

   2. Exciting no pity; as, a pitiless condition.
      [1913 Webster] -- {Pit"i*less*ly}, adv. --
      {Pit"i*less*ness}, n.
      [1913 Webster]

from Moby Thesaurus II by Grady Ward, 1.0

50 Moby Thesaurus words for "pitilessness":
      acuteness, animality, atrocity, barbarity, bloodlust, brutality,
      callosity, callousness, coldbloodedness, coldheartedness, coldness,
      destructiveness, extremity, ferociousness, fierceness, force,
      furiousness, hardheartedness, hardness, hardness of heart,
      harshness, heart of stone, heartlessness, impetuosity, inclemency,
      inhumanity, insensitivity, intensity, malignity, mercilessness,
      mindlessness, murderousness, obduracy, rigor, roughness, savagery,
      severity, sharpness, terrorism, unfeeling, ungentleness,
      unmercifulness, unnaturalness, unresponsiveness, vandalism,
      vehemence, venom, viciousness, violence, virulence