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. ]