The Collaborative International Dictionary of English v.0.48:

Chemosynthesis \Chem`o*syn"the*sis\, n. [Chemical + synthesis.]
   (Plant Physiol.)
   Synthesis of organic compounds by energy derived from
   chemical changes or reactions. Chemosynthesis of
   carbohydrates occurs in the nitrite bacteria through the
   oxidation of ammonia to nitrous acid, and in the nitrate
   bacteria through the conversion of nitrous into nitric acid.
   -- Chem`o*syn*thet"ic, a.
   [Webster 1913 Suppl.] Chemotaxis

WordNet (r) 3.0 (2006):

chemosynthesis
    n 1: synthesis of carbohydrate from carbon dioxide and water;
         limited to certain bacteria and fungi