Source : Webster's Revised Unabridged Dictionary (1913)

Permeation \Per`me*a"tion\, n.
   The act of permeating, passing through, or spreading
   throughout, the pores or interstices of any substance.

         Here is not a mere involution only, but a spiritual
         permeation and inexistence.              --Bp. Hall.

Source : WordNet®

permeation
     n 1: the process of permeating or infusing something with a
          substance [syn: {pervasion}, {suffusion}]
     2: mutual penetration; diffusion of each through the other
        [syn: {interpenetration}]