/ˈɪnfɪlˌtreɪt/
[T, I] to enter or make sb enter a place or an organization secretly, especially in order to get information that can be used against it （使）悄悄进入，潜入
~ sth
The headquarters had been infiltrated by enemy spies.
总部混入了敌方特务。
~ sb into sth
Rebel forces were infiltrated into the country.
反叛力量潜入了这个国家。
~ into sth
The CIA agents successfully infiltrated into the terrorist organizations.
中央情报局的特工人员成功地渗入了恐怖分子组织。