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]

Moby Thesaurus II by Grady Ward, 1.0:

66 Moby Thesaurus words for "permeate":
   bathe, bespread, besprinkle, breathe, brew, charge, color,
   crawl with, creep with, decoct, diffuse, douche, dredge, drench,
   drouk, dye, enter, entincture, extend throughout, fill, flavor,
   flush, honeycomb, imbrue, imbue, impregnate, infiltrate, infuse,
   ingrain, inject, instill, interfuse, interpenetrate, invade, lave,
   leach, leave no void, leaven, lixiviate, macerate, occupy, overrun,
   overspread, overswarm, penetrate, percolate, pervade, rinse,
   run through, saturate, season, seethe, soak, sodden, sop, souse,
   steep, suffuse, swarm with, teem with, temper, tincture, tinge,
   transfuse, wash, waterlog