Percolate means to filter or trickle through a porous substance. Two examples of percolation include ground coffee in a filter or rainwater through soil on its way to an aquifer. The word comes from Latin "perc?l?tus," meaning "to filter."
Percolation is the part of the water cycle in which water drips through loose, aerated soil because of gravity. Once percolated water reaches the water table, it remains underground until it reaches a spring and becomes a stream or river. Percolated freshwater becomes drinking water for humans who access this water through wells.
Coffee percolators run hot water through the top of the contraption before it mixes with coffee grounds. A paper filter then allows the water and coffee mix to run into a cup without the ground coffee beans.