Source : Webster's Revised Unabridged Dictionary (1913)

Sentience \Sen"ti*ence\, Sentiency \Sen"ti*en*cy\, n. [See
   {Sentient}, {Sentence}.]
   The quality or state of being sentient; esp., the quality or
   state of having sensation. --G. H. Lewes

         An example of harmonious action between the
         intelligence and the sentieny of the mind. --Earle.

Source : WordNet®

sentiency
     n : the faculty through which the external world is apprehended;
         "in the dark he had to depend on touch and on his senses
         of smell and hearing" [syn: {sense}, {sensation}, {sentience},
          {sensory faculty}]