infiltrate

American  

[in-fil-treyt, in-fil-treyt] / ɪnˈfɪl treɪt, ˈɪn fɪlˌtreɪt /

verb (used with object)

infiltrated, infiltrating

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, especially 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.

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verb (used without object)

infiltrated, infiltrating

1. to pass into or through a substance, place, etc., by or as by filtering.

2. Pathology. to penetrate tissue spaces or cells.

noun

1. something that infiltrates.

2. Pathology. any substance penetrating tissues or cells and forming a morbid accumulation.

infiltrate British  

/ ˈɪnfɪlˌtreɪt /

verb

1. to undergo or cause to undergo the process in which a fluid passes into the pores or interstices of a solid; permeate

2. military to pass undetected through (an enemy-held line or position)

3. to gain or cause to gain entrance or access surreptitiously

   they infiltrated the party structure

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noun

1. something that infiltrates

2. pathol any substance that passes into and accumulates within cells, tissues, or organs

3. pathol a local anaesthetic solution injected into the tissues to cause local anaesthesia

Other Word Forms

• infiltration noun
• infiltrative adjective
• infiltrator noun
• reinfiltrate verb
• uninfiltrated adjective

Etymology

Origin of infiltrate

First recorded in 1750–60; in- ² + filtrate

Example Sentences

There isn’t an easy solution to stopping microplastics—minuscule particles from plastic products such as water bottles—from infiltrating the environment, and ultimately our bodies.

From The Wall Street Journal

In Maui, the opening of “Die Another Day” shows James Bond and two other surfers riding massive waves to infiltrate North Korea.

From The Wall Street Journal

Once an online group is infiltrated, malicious AI swarms can create the illusion of broad public agreement around the narratives they are programmed to promote.

From Salon

China's sprawling security apparatus has long been accused of infiltrating community organisations as a way to keep tabs on expats and dissidents.

From Barron's

Now, with several decades of food-standards work under her belt, Elahi remains alert to the possibility of fraud infiltrating other types of foods.

From BBC

Related Words

• penetrate
• permeate
• pervade