definition of infiltrating
infiltrate inÂ·filÂ·trate (Ä­n-fÄ­l'trÄt', Ä­n'fÄ­l-) v. inÂ·filÂ·tratÂ·ed, inÂ·filÂ·tratÂ·ing, inÂ·filÂ·trates. To cause a liquid to permeate a substance by passing through its interstices or pores. To permeate a porous substance with a liquid or gas.