infiltrate
verb/ĩfiɫˈtɾaɾ/medium
in·fil·trar
Definition
1. To enter or gain access to (an organization, place, etc.) surreptitiously and gradually, especially to acquire secret information. 2. (Of a liquid) to pass gradually into or through a substance by filtering or permeating.
The spy managed to infiltrate the enemy's high command.
Pollutants have infiltrated the groundwater supply.
Common collocations
infiltrate an organizationwater infiltratesinfiltrate agents
Etymology
Do latim 'infiltrare', de 'in-' + 'filtrare' ('filtrar').