Source : Webster's Revised Unabridged Dictionary (1913)

Caffetannic \Caf`fe*tan"nic\, a. [Caffeic + tannic.] (Chem.)
   Pertaining to, or derived from, the tannin of coffee.

   {Caffetannic acid}, a variety of tannin obtained from coffee
      berries, regarded as a glucoside.