動詞 infiltrate:

1. cause (a liquid) to enter by penetrating the interstices
2. enter a group or organization in order to spy on the members
   同義詞：penetrate
3. pass into or through by filtering or permeating
4. pass through an enemy line; in a military conflict
   同義詞：pass through

1. He joined the party and turned out to be a wolf in sheep's clothing because he was sent to infiltrate our group for the extreme right wingers.
   他加入了我們的黨，結(jié)果卻是一只披著羊皮的豺狼，因為他是被極右分子派來混在我們的團體之中的。
2. Beware of the fifth column. They often infiltrate into key positions and seek to undermine the body politic from within.
   要提防隱蔽的敵人，他們經(jīng)常滲透到關(guān)鍵崗位企圖從內(nèi)部破壞國家政體。
3. The teacher tried to infiltrate her ideas into the children's minds.
   老師設(shè)法把她的思想滲透到孩子們的心中。

in.fil.trate

v.（動詞）
in.fil.trat.ed,in.fil.trat.ing,in.fil.trates
v.tr.（及物動詞）

To pass (troops, for example) surreptitiously into enemy-held territory.
潛入：偷偷將（如軍隊）派遣進入敵人占領(lǐng)的地區(qū)
To penetrate with hostile intent:
滲透：懷著敵意而滲透進入：
例句：
infiltrate enemy lines; a team of terrorists that had infiltrated the country.
滲入敵軍防線；一隊滲入該國的恐怖分子

To enter or take up positions in gradually or surreptitiously, as for purposes of espionage or takeover:
混入，接收：秘密地或逐漸地進入或獲取職位，目的是間諜行為或掌握政權(quán)：
例句：
tried to infiltrate key government agencies with spies.
派間諜試圖滲透進政府的關(guān)鍵職位

To cause (a liquid, for example) to permeate a substance by passing through its interstices or pores.
滲透：透過間隙或小孔使一種物質(zhì)（如水）滲過另一種物質(zhì)
To permeate (a porous substance) with a liquid or gas.
使浸透：用水或氣體穿過多孔物質(zhì)
v.intr.（不及物動詞）
To gain entrance gradually or surreptitiously.
滲透：逐漸地或秘密地獲得進入權(quán)
n.（名詞）
One that infiltrates, especially an abnormal substance that accumulates gradually in cells or body tissues.
滲透物：能滲透的物質(zhì)，尤指一種能在細胞或人體組織中聚集的異常物質(zhì)

【引伸】
infil.trator
n.（名詞）