The Collaborative International Dictionary of English v.0.48:

Hedonic \He*don"ic\, a. [Gr. ?, fr. ? pleasure, ? sweet,
   pleasant.]
   1. Pertaining to pleasure.
      [1913 Webster]

   2. Of or relating to Hedonism or the Hedonic sect.
      [1913 Webster]

   Hedonic sect a sect that placed the highest good in the
      gratification of the senses, -- called also Cyrenaic
      sect, (which see), and School of Aristippus.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hedonic
    adj 1: devoted to pleasure; "a hedonic thrill"; "lives of
           unending hedonistic delight"; "epicurean pleasures" [syn:
           hedonic, hedonistic, epicurean]