The Collaborative International Dictionary of English v.0.48:

Conductance \Con*duct"ance\ (k[o^]n*d[u^]k"tans), n. [Conduct,
   v. + -ance.] (Elec.)
   Conducting power; -- the reciprocal of resistance. A
   suggested unit is the mho, the reciprocal of the ohm.

         Conductance is an attribute of any specified conductor,
         and refers to its shape, length, and other factors.
         Conductivity is an attribute of any specified material
         without direct reference to its shape or other factors.
                                                  --Sloane's
                                                  Elec. Dict.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

conductance
    n 1: a material's capacity to conduct electricity; measured as
         the reciprocal of electrical resistance

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "conductance":
   conduction, conductivity, conductor, dielectric,
   electric conduction, electrode conductance, gas conduction,
   grid conductance, input conductance, insulator, ionic conduction,
   liquid conduction, metallic conduction, mho, nonconductor,
   output conductance, photoconduction, plate conductance,
   semiconductor, superconductivity, superconductor,
   transfer conductance