infiltrate
intransitive verbTo pass (troops, for example) surreptitiously into enemy-held territory.
intransitive verbTo penetrate with hostile intent.
intransitive verbTo enter or take up positions in gradually or surreptitiously, as for purposes of espionage or takeover.
intransitive verbTo cause (a liquid, for example) to permeate a substance by passing through its interstices or pores.
intransitive verbTo permeate (a porous substance) with a liquid or gas.
intransitive verbTo gain entrance gradually or surreptitiously.
nounOne that infiltrates, especially an abnormal substance that accumulates gradually in cells or body tissues.
To pass by filtration; percolate through pores or interstices.
To pass into or through the pores or interstices of; filter into or through.