Source : Webster's Revised Unabridged Dictionary (1913)

Pervasion \Per*va"sion\, n. [L. pervasio. See {Pervade}.]
   The act of pervading, passing, or spreading through the whole
   extent of a thing. --Boyle.

Source : WordNet®

pervasion
     n : the process of permeating or infusing something with a
         substance [syn: {permeation}, {suffusion}]