Source : Webster's Revised Unabridged Dictionary (1913)

Permeability \Per`me*a*bil"i*ty\, n. [Cf. F.
   perm['e]abilit['e].]
   The quality or state of being permeable.

   {Magnetic permeability} (Physics), the specific capacity of a
      body for magnetic induction, or its conducting power for
      lines of magnetic force. --Sir W. Thomson.

Source : WordNet®

permeability
     n : the property of something that can be pervaded by a liquid
         (as by osmosis or diffusion) [syn: {permeableness}] [ant:
          {impermeability}]