The Collaborative International Dictionary of English v.0.48:

Apathetic \Ap`a*thet"ic\, Apathetical \Ap`a*thet"ic*al\a. [See
   Apathy.]
   Void of feeling; not susceptible of deep emotion;
   passionless. a woman who became active rather than apathetic
   as she grew older
   [1913 Webster]

   2. showing a lack of interest or concern; indifferent. an
      apathetic audience

   Syn: indifferent
        [WordNet 1.5]