S: (v) trickle, dribble, filter (run or flow slowly, as in drops or in an unsteady stream) "water trickled onto the lawn from the broken hose"; "reports began to dribble in"
S: (v) leach, percolate (permeate or penetrate gradually) "the fertilizer leached into the ground"
W: (n) percolation [Related to: percolate] (the slow passage of a liquid through a filtering medium) "the percolation of rainwater through the soil"; "the infiltration of seawater through the lava"