The Collaborative International Dictionary of English v.0.48:

Alienation \Al`ien*a"tion\, n. [F. ali['e]nation, L. alienatio,
   fr. alienare, fr. alienare. See Alienate.]
   1. The act of alienating, or the state of being alienated.
      [1913 Webster]

   2. (Law) A transfer of title, or a legal conveyance of
      property to another.
      [1913 Webster]

   3. A withdrawing or estrangement, as of the affections.
      [1913 Webster]

            The alienation of his heart from the king. --Bacon.
      [1913 Webster]

   4. Mental alienation; derangement of the mental faculties;
      insanity; as, alienation of mind.
      [1913 Webster]

   Syn: Insanity; lunacy; madness; derangement; aberration;
        mania; delirium; frenzy; dementia; monomania. See
        Insanity.
        [1913 Webster]

WordNet (r) 3.0 (2006):

alienation
    n 1: the feeling of being alienated from other people [syn:
         alienation, disaffection, estrangement]
    2: separation resulting from hostility [syn: alienation,
       estrangement]
    3: (law) the voluntary and absolute transfer of title and
       possession of real property from one person to another; "the
       power of alienation is an essential ingredient of ownership"
    4: the action of alienating; the action of causing to become
       unfriendly; "his behavior alienated the other students"