The Collaborative International Dictionary of English v.0.48:

Permeate \Per"me*ate\, v. t. [imp. & p. p. Permeated; p. pr. &
   vb. n. Permeating.] [L. permeatus, p. p. of permeare to
   permeate; per + meare to go, pass.]
   1. To pass through the pores or interstices of; to penetrate
      and pass through without causing rupture or displacement;
      -- applied especially to fluids which pass through
      substances of loose texture; as, water permeates sand.
      --Woodward.
      [1913 Webster]

   2. To enter and spread through; to pervade; as, after the
      first setback, the team became permeated with pessimism.
      [1913 Webster]

            God was conceived to be diffused throughout the
            whole world, to permeate and pervade all things.
                                                  --Cudworth.
      [1913 Webster]

WordNet (r) 3.0 (2006):

permeate
    v 1: spread or diffuse through; "An atmosphere of distrust has
         permeated this administration"; "music penetrated the
         entire building"; "His campaign was riddled with
         accusations and personal attacks" [syn: permeate,
         pervade, penetrate, interpenetrate, diffuse,
         imbue, riddle]
    2: pass through; "Water permeates sand easily" [syn:
       percolate, sink in, permeate, filter]
    3: penetrate mutually or be interlocked; "The territories of two
       married people interpenetrate a lot" [syn: interpenetrate,
       permeate]