percolation

percolation
    n 1: the slow passage of a liquid through a filtering medium;
         "the percolation of rainwater through the soil"; "the
         infiltration of seawater through the lava" [syn:
         {percolation}, {infiltration}]
    2: the act of making coffee in a percolator
    3: the filtration of a liquid for extraction or purification
    

Percolation \Per`co*la"tion\, n. [L. percolatio.]
   The act or process of percolating, or filtering; filtration;
   straining. Specifically (Pharm.), the process of exhausting
   the virtues of a powdered drug by letting a liquid filter
   slowly through it.
   [1913 Webster]
    

133 Moby Thesaurus words for "percolation":
      absorbency, absorbent, absorption, access, admission, adsorbent,
      adsorption, assimilation, blotter, blotting, blotting paper,
      bolting, brewing, chemisorption, chemosorption, clarification,
      colature, colliquation, condensation, decoagulation, deliquescence,
      deliquium, destructive distillation, digestion, dissolution,
      dissolving, distillation, drench, drenching, dribble, drip,
      dripping, drop, ducking, dunking, edulcoration, effusion, elution,
      elutriation, endosmosis, engrossment, entrance, entree, entry,
      essentialization, excretion, exfiltration, exosmosis, extraction,
      extravasation, exudation, filtering, filtration, fluidification,
      fluidization, fusing, fusion, imbruement, imbuement, import,
      importation, importing, impregnation, income, incoming,
      infiltration, infusion, ingoing, ingress, ingression, injection,
      input, insertion, insinuation, intake, interpenetration,
      introduction, introgression, intrusion, leaching, leakage,
      liquefaction, liquescence, liquescency, lixiviation, maceration,
      melting, ooze, oozing, osmosis, penetration, percolating,
      permeation, pulping, purification, reception, refinement, riddling,
      running, saturation, screening, seep, seepage, seeping, seething,
      separation, sieving, sifting, soak, soakage, soaking,
      solubilization, solution, sopping, sorption, souse, sousing,
      spiritualization, sponge, sponging, spurtle, steeping, straining,
      sublimation, sweating, thawing, transudation, trickle, tricklet,
      unclotting, weep, weeping, winnowing