Source : Webster's Revised Unabridged Dictionary (1913)

Enzyme \En"zyme\, n. [Pref. en- (Gr. ? in) + Gr. ? leaven.]
   (Physiol. Chem.)
   An unorganized or unformed ferment, in distinction from an
   organized or living ferment; a soluble, or chemical, ferment.
   Ptyalin, pepsin, diastase, and rennet are good examples of
   enzymes.

Source : WordNet®

enzyme
     n : any of several complex proteins that are produced by cells
         and act as catalysts in specific biochemical reactions