Source : Webster's Revised Unabridged Dictionary (1913)

Supposal \Sup*pos"al\, n.
   The act of supposing; also, that which is supposed;
   supposition; opinion. --Shak.

         Interest, with a Jew, never proceeds but upon supposal,
         at least, of a firm and sufficient bottom. --South.

Source : WordNet®

supposal
     n 1: a hypothesis that is taken for granted; "any society is
          built upon certain assumptions" [syn: {assumption}, {supposition}]
     2: the cognitive process of supposing [syn: {supposition}]