Infiltration Moderate

a process in which individuals (or small groups) penetrate an area (especially the military penetration of enemy positions without detection)

"The special forces team executed a silent infiltration of the fortress to capture the commander before dawn."

the slow passage of a liquid through a filtering medium

"the percolation of rainwater through the soil"

"the infiltration of seawater through the lava"

The act or process of infiltrating, as of water into a porous substance, or of a fluid into the cells of an organ or part of the body.

"The heavy rain caused significant infiltration of groundwater into the dry soil beneath the garden beds."