The Collaborative International Dictionary of English v.0.48:

Aphetic \A*phet"ic\, a. [Gr. ? letting go, fr. ? to let go.]
   Shortened by dropping a letter or a syllable from the
   beginning of a word; as, an aphetic word or form. --
   A*phet"ic*al*ly, adv. --New Eng. Dict.
   [1913 Webster]

WordNet (r) 3.0 (2006):

aphetic
    adj 1: produced by aphesis