1 infiltrate | Definition of infiltrate

infiltrate

verb
in·​fil·​trate | \ in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) , ˈin-(ˌ)fil- How to pronounce infiltrate (audio) \
infiltrated; infiltrating

Definition of infiltrate

transitive verb

1 : to cause (something, such as a liquid) to permeate something by penetrating its pores or interstices
2 : to pass into or through (a substance) by filtering or permeating
3 : to pass (troops) singly or in small groups through gaps in the enemy line
4 : to enter or become established in gradually or unobtrusively usually for subversive purposes the intelligence staff had been infiltrated by spies

intransitive verb

: to enter, permeate, or pass through a substance or area by filtering or by insinuating gradually

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Other Words from infiltrate

infiltrate noun
infiltration \ ˌin-​(ˌ)fil-​ˈtrā-​shən How to pronounce infiltration (audio) \ noun
infiltrative \ ˈin-​(ˌ)fil-​ˌtrā-​tiv How to pronounce infiltrative (audio) , in-​ˈfil-​trə-​ \ adjective
infiltrator \ in-​ˈfil-​ˌtrā-​tər How to pronounce infiltrator (audio) , ˈin-​(ˌ)fil-​ How to pronounce infiltrator (audio) \ noun

Synonyms for infiltrate

Synonyms

insinuate, slip, sneak, wind, work in, worm, wriggle

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Examples of infiltrate in a Sentence

The gang was infiltrated by undercover agents. Attempts to infiltrate undercover agents into the gang have failed. Water can easily infiltrate the soil.
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Recent Examples on the Web

The archaeological site was beset by labor strife, work crews had been infiltrated by the powerful Naples Camorra mafia, buildings were crumbling at an alarming rate. Chiara Goia, Smithsonian, "The New Treasures of Pompeii," 21 Aug. 2019 And there’s a big one that every 21st-century business grapples with every day: hackers who relentlessly try to infiltrate computer networks and steal sensitive information. Jonathan Vanian, Fortune, "Meet Chronicle, Alphabet's Latest Moonshot," 19 Feb. 2018 Pastor Albert Rivera, who runs the Agape shelter, said several months ago, a man who pretended to be migrant infiltrated the Agape shelter and began working as a pollero, convincing some young women to try to cross into the United States with him. San Diego Union-Tribune, "Asylum seekers targeted by kidnappers, extortionists and traffickers while waiting in Mexico," 29 July 2019 Two years ago, journalists from Reuters uncovered that since the FTCT’s creation, PMI has infiltrated and encouraged dissent in delegate meetings about tobacco regulation. Katherine Ellen Foley, Quartz, "The world’s largest tobacco company’s anti-smoking campaign relies on smokers," 26 July 2019 For years, Mexico relied on the military to confront organized crime, in some cases even disbanding local police forces because they had been infiltrated by cartels. Elizabeth Llorente, Fox News, "Mexico murder rate reaches all-time high," 4 July 2019 Al Qaeda operatives also worried that Zarqawi’s network might have been infiltrated by Jordanian intelligence. Ben Taub, The New Yorker, "The Law That Makes It Easy to Go to War with Iran," 27 June 2019 To neutralize the threat to their homes, these former rivals tap into new secret agent gadgets to infiltrate her base of operations. Nick Romano, EW.com, "Birds and pigs go all 007 in final Angry Birds Movie 2 trailer," 20 June 2019 But within a year Hitler closed it, claiming the movement was infiltrated with Jews and Communists. Margo Pfeiff, latimes.com, "Exploring the birthplace of Bauhaus, a German movement that changed design," 16 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infiltrate.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of infiltrate

1758, in the meaning defined at transitive sense 1

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More Definitions for infiltrate

infiltrate

verb

English Language Learners Definition of infiltrate

: to secretly enter or join (something, such as a group or an organization) in order to get information or do harm
: to cause (someone) to secretly enter or join a group, organization, etc.
technical : to pass into or through (something)

infiltrate

verb
in·​fil·​trate | \ in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) , ˈin-(ˌ) How to pronounce infiltrate (audio) \
infiltrated; infiltrating

Medical Definition of infiltrate

 (Entry 1 of 2)

transitive verb

1 : to cause (as a liquid) to permeate something by penetrating its pores or interstices infiltrate tissue with a local anesthetic
2 : to pass into or through (a substance) by filtering or permeating

intransitive verb

: to enter, permeate, or pass through a substance or area

infiltrate

noun

Medical Definition of infiltrate (Entry 2 of 2)

: something that passes or is caused to pass into or through something by permeating or filtering especially : a substance that passes into the bodily tissues and forms an abnormal accumulation a lung infiltrate