Source : Webster's Revised Unabridged Dictionary (1913)

Zymotic \Zy*mot"ic\, a. [Gr. ? causing to ferment, fr. ? to
   ferment, ? ferment, leaven.]
   1. Of, pertaining to, or caused by, fermentation.

   2. (Med.) Designating, or pertaining to, a certain class of
      diseases. See {Zymotic disease}, below.

   {Zymotic disease} (Med.), any epidemic, endemic, contagious,
      or sporadic affection which is produced by some morbific
      principle or organism acting on the system like a ferment.