The Collaborative International Dictionary of English v.0.48:

Unfeeling \Un*feel"ing\, a.
   1. Destitute of feeling; void of sensibility; insensible;
      insensate.
      [1913 Webster]

   2. Without kind feelings; cruel; hard-hearted.
      [1913 Webster]

            To each his sufferings: all are men,
            Condemned alike to groan;
            The tender for another's pain,
            Th' unfeeling for his own.            --Gray.
      [1913 Webster] -- Un*feel"ing*ly, adv. --
      Un*feel"ing*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unfeeling
    adj 1: devoid of feeling for others; "an unfeeling wretch" [syn:
           hardhearted, stonyhearted, unfeeling]
    2: devoid of feeling or sensation; "unfeeling trees"