The Collaborative International Dictionary of English v.0.48:

Autocatalysis \Au`to*ca*tal"y*sis\, n. [Auto- + catalysis.]
   (Chem.)
   Self-catalysis; catalysis of a substance by one of its own
   products, as of silver oxide by the silver formed by
   reduction of a small portion of it. -- Au`to*cat`a*lyt"ic,
   a.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

autocatalysis
    n 1: catalysis in which the catalyst is one of the products of
         the reaction