percolator
    n 1: a coffeepot in which boiling water ascends through a
         central tube and filters back down through a basket of
         ground coffee beans

Percolator \Per"co*la`tor\, n.
   1. One who, or that which, filters. "[Tissues] act as
      percolators." --Henfrey.
      [1913 Webster]

   2. A type of coffee pot in which the heated water is driven
      by its boiling action up above a porous canister of coffee
      held above the level of the water in the pot, and then
      filters (percolates) back through the coffee thus
      extracting its essence.
      [Webster 1913 Suppl. +PJC]

   3. (Pharmacy) An apparatus for producing an extract from a
      drug by percolation.
      [Webster 1913 Suppl.]