Source : Webster's Revised Unabridged Dictionary (1913)

Premiss \Prem"iss\, n.
   Premise. --Whately. I. Watts

Source : WordNet®

premiss
     n : a statement that is assumed to be true and from which a
         conclusion can be drawn; "on the assumption that he has
         been injured we can infer that he will not to play" [syn:
          {premise}, {assumption}]
     v : take something as preexisting and given [syn: {premise}]