The Collaborative International Dictionary of English v.0.48:

Appealable \Ap*peal"a*ble\, a.
   1. Capable of being appealed against; that may be removed to
      a higher tribunal for decision; as, the cause is
      appealable.
      [1913 Webster]

   2. That may be accused or called to answer by appeal; as, a
      criminal is appealable for manslaughter. [Obs.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

appealable
    adj 1: capable of being appealed especially to a higher
           tribunal; "decisions...appealable to the head of the
           agency"- New Republic [ant: unappealable]