infiltrate

verb

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

transitive verb

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

intransitive verb

: to enter, permeate, or pass through a substance or area by filtering or by insinuating gradually
infiltrate noun
infiltration noun
infiltrative
ˈin-(ˌ)fil-ˌtrā-tiv How to pronounce infiltrate (audio)
in-ˈfil-trə-
adjective

Example Sentences

The gang was infiltrated by undercover agents. Attempts to infiltrate undercover agents into the gang have failed. Water can easily infiltrate the soil.
Recent Examples on the Web But with so many companies investing specifically in email protection as the primary defense strategy, the bad guys are quickly realizing that email is not the only method to infiltrate employees to get their hands on critical company data. Patrick Harr, Forbes, 9 Mar. 2023 Because the aquarium pumps in saltwater for its tanks, whatever agent is infecting sea stars outside could infiltrate the exhibits. Dino Grandoni, Anchorage Daily News, 5 Mar. 2023 But in our extremely online age, the same news, chaos, and drama that makes the perfect fodder for a documentary can infiltrate the work itself, making a film the center of discourse — sometimes, long before anyone has ever seen it. Ct Jones, Rolling Stone, 2 Mar. 2023 Witness accounts and a Times video analysis reveal how Iran’s security forces are co-opting ambulances to infiltrate demonstrations and detain protesters. Vivian Yee, New York Times, 28 Dec. 2022 Their end game, detractors say, is to infiltrate New Hampshire government at all levels — from select boards to the State House — with the aim of dismantling it. Brian Macquarrie, BostonGlobe.com, 3 Sep. 2022 It’s had time to infiltrate the childhood memories of generations of readers—and perhaps influence their accessory choices, too. Nancy Macdonell, WSJ, 24 Aug. 2022 After detailing the first three steps to infiltrate the buildings, storm them and distract law enforcement, the plan reaches its goals. Will Carless, USA TODAY, 16 June 2022 In mice, microglia originate in the yolk sac of an embryo and then infiltrate the brain early in development. Kristine Zengeler, Discover Magazine, 10 Dec. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'infiltrate.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1758, in the meaning defined at transitive sense 4

Time Traveler
The first known use of infiltrate was in 1758

Dictionary Entries Near infiltrate

Cite this Entry

“Infiltrate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infiltrate. Accessed 1 Apr. 2023.

Kids Definition

infiltrate

verb
in·​fil·​trate in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) ˈin-(ˌ)fil- How to pronounce infiltrate (audio)
infiltrated; infiltrating
1
: to pass into or through by filtering
2
: to enter or become established gradually or secretly
infiltration noun

Medical Definition

infiltrate

1 of 2 verb
in·​fil·​trate in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) ˈin-(ˌ) How to pronounce infiltrate (audio)
infiltrated; infiltrating

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

2 of 2 noun
: 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

More from Merriam-Webster on infiltrate

Last Updated: - Updated example sentences
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