The Collaborative International Dictionary of English v.0.48:

Excommunicable \Ex`com*mu"ni*ca*ble\, a. [See Excommunicate.]
   Liable or deserving to be excommunicated; making
   excommunication possible or proper. "Persons excommunicable
   ." --Bp. Hall.
   [1913 Webster]

         What offenses are excommunicable ?       --Kenle.
   [1913 Webster]