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

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.
Recent Examples on the Web Garlic mustard, Asian bush honeysuckle and autumn olive can infiltrate areas and destroy the diversity of natural landscapes. Karl Schneider, The Indianapolis Star, 18 Mar. 2024 For decades, cartels have infiltrated all levels of government — financing campaigns, making deals with candidates, and even killing when their needs are not met. Karol Suárez, The Courier-Journal, 11 Mar. 2024 Now that the Swifties have officially infiltrated the NFL, what better place for Taylor Swift to preview Reputation (Taylor's Version) than on a documentary series about the New England Patriots? Kathleen Walsh, Glamour, 7 Mar. 2024 Lem, in other words, was an avatar of the Communist Party machine, and that machine was infiltrating American thinking. Rivka Galchen, The New Yorker, 27 Feb. 2024 Pests and wildlife have at times infiltrated its campuses, including an incident where a garter snake entered a Boulder building. Cat Zakrzewski, Washington Post, 6 Mar. 2024 Encinas’s phone, and those of several human-rights defenders, have been infiltrated by Pegasus. Alma Guillermoprieto, The New Yorker, 4 Mar. 2024 The film sheds light on a pivotal moment during the freedom struggle in South Africa, when the politician and activist Oliver Tambo hatched a plan to infiltrate young British activists posing as tourists into the country, to help inspire ordinary South Africans to join the liberation movement. Christopher Vourlias, Variety, 3 Mar. 2024 The town of Aspen has been infiltrated with traditional fashion brands but has been leaning toward true winter fashion from brands like Aztech Mountain, Aspen X, and Fusalp, to name a few. Cassell Ferere, Forbes, 26 Feb. 2024

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 29 Mar. 2024.

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

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