The Collaborative International Dictionary of English v.0.48:

Equipollent \E`qui*pol"lent\, a. [L. aequipollens; aequus equal
   + pollens, -entis, p. pr. of pollere to be strong, able: cf.
   F. ['e]quipollent.]
   1. Having equal power or force; equivalent. --Bacon.
      [1913 Webster]

   2. (Logic) Having equivalent signification and reach;
      expressing the same thing, but differently.
      [1913 Webster]