equipollence

from The Collaborative International Dictionary of English v.0.48

Equipollence \E`qui*pol"lence\, Equipollency \E`qui*pol"len*cy\,
   n. [Cf. F. ['e]quipollence. See {Equipollent}.]
   1. Equality of power, force, signification, or application.
      --Boyle.
      [1913 Webster]

   2. (Logic) Sameness of signification of two or more
      propositions which differ in language.
      [1913 Webster]