/'ɪnfɪltreɪt; ɪn`fɪltret/
v
1 [I, Ipr] ~ (through sth) (into sth) (of liquids, gases, etc) pass slowly by filtering; penetrate （指液体、气体等）渗透, 透入
*The thick fog seemed to have infiltrated through the very walls into the room. 浓雾好像透过墙壁进到房间里.
* (fig 比喻) the depths of the ocean, where no light can infiltrate 海洋的深处, 光线射不进去.
2 [Tn.pr] ~ A into B/~ B with A cause sth to pass slowly by filtering it into sth else 使某物慢慢渗入或透入他物
*infiltrate poison into the water-supply/infiltrate the water-supply with poison 把毒药慢慢渗入水源.
3 [Ipr, Tn] ~ (through sth) (into sth) (esp military or politics 尤用于军事或政治) enter (sth) stealthily without being noticed 悄悄进入; 潜入
*troops infiltrating through enemy lines into occupied territory 通过敌人封锁线潜入占领区的部队
* Our entire organization had been infiltrated by enemy agents. 敌特已打入我们整个组织.
4 [Tn.pr] (esp military or politics 尤用于军事或政治) ~ sb/sth into sth; ~ sth with sb/sth introduce sb/sth stealthily into sth 暗中使某人[某事物]进入
*infiltrate spies into a country 派间谍进入某国家
* infiltrate an organization with one's own men 派自己的人混入某组织.

v
[>I always + adv/prep, T]
to secretly join an organization or enter a place in order to find out information about it or harm it
　Police attempts to infiltrate neo-Nazi groups were largely unsuccessful.
infiltrate into
　Rebel forces have been infiltrating into the country.
[T]
to secretly put people into an organization or place in order to find out information or to harm it
infiltrate sb into sth
　They repeatedly tried to infiltrate assassins into the palace.
[T]
to become a part of something - used especially to show disapproval
　Commercialism has been infiltrating universities for the past decade.
>infiltratorn[C]
>infiltration [,ɪnfɪl'treɪʃən/