The Collaborative International Dictionary of English v.0.48:

Autotrophic \Au`to*troph"ic\, a. [Auto- + trophic.] (Plant
   Physiol.)
   Capable of self-nourishment; requiring only minerals for
   growth; using carbonate or carbon dioxide as a source of
   carbon and simple inorganic nitrogen as a nitrogen source; --
   said of all plants in which photosynthetic activity takes
   place, and certain bacteria. It is opposed to parasitism or
   saprophytism.
   [Webster 1913 Suppl. + WordNet 1.5]

   2. of or pertaining to an autotroph.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

autotrophic
    adj 1: of or relating to organisms (as green plants) that can
           make complex organic nutritive compounds from simple
           inorganic sources by photosynthesis [syn: autotrophic,
           autophytic] [ant: heterotrophic]