infiltrate: Meaning and Definition of

in•fil•trate

1. to filter into or through; permeate.
2. to cause to pass in by filtering.
3. to move into (an organization, country, territory, or the like) surreptitiously and gradually, esp. with hostile intent: The troops infiltrated the enemy lines.
4. to pass a small number of (soldiers, spies, or the like) into a territory or organization clandestinely and with hostile or subversive intent: The intelligence agency infiltrated three spies into the neighboring country.

1. to pass into or through a substance, place, etc., by or as by filtering.
2. to penetrate tissue spaces or cells.

1. something that infiltrates.
2. any substance penetrating tissues or cells and forming a morbid accumulation.