The Collaborative International Dictionary of English v.0.48:
Metabolite \Me*tab"o*lite\, n. (Physiol Chem.) A product of metabolism; a substance produced by metabolic action, as urea. [1913 Webster]WordNet (r) 3.0 (2006):
metabolite n 1: any substance involved in metabolism (either as a product of metabolism or as necessary for metabolism)