infiltrate
verb
in·fil·trate
ˈin-(ˌ)fil-ˌtrāt 
in-ˈfil-
in-ˈfil-
infiltrated; infiltrating
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
: to enter, permeate, or pass through a substance or area by filtering or by insinuating gradually
infiltrate
noun
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
Third, Operation Gold Rush highlights how international fraud rings have infiltrated federal programs to steal personal information and American tax dollars.
—
Nicholas Creel, MSNBC Newsweek, 9 July 2025
Introduced globally in 2021 as a 2022 model, Hyundai hoped the Ioniq 5 and its expanding lineup of siblings would infiltrate the market.
—James Raia, Mercury News, 6 July 2025
Maybe predators will infiltrate the hen house, the ends of a fence don’t quite align or a mama will crush her litter.
—Bennet Goldstein, jsonline.com, 4 July 2025
Native plants enhance soil permeability with their deep root systems, which create channels that allow rainwater to infiltrate and percolate deeper into the ground.
—Claire Marks, Austin American Statesman, 2 July 2025
See All Example Sentences for infiltrate
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Nicholas Creel, MSNBC Newsweek, 9 July 2025
Introduced globally in 2021 as a 2022 model, Hyundai hoped the Ioniq 5 and its expanding lineup of siblings would infiltrate the market.
—James Raia, Mercury News, 6 July 2025
Maybe predators will infiltrate the hen house, the ends of a fence don’t quite align or a mama will crush her litter.
—Bennet Goldstein, jsonline.com, 4 July 2025
Native plants enhance soil permeability with their deep root systems, which create channels that allow rainwater to infiltrate and percolate deeper into the ground.
—Claire Marks, Austin American Statesman, 2 July 2025
See All Example Sentences for infiltrate
Cite this Entry
“Infiltrate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infiltrate. Accessed 23 Jul. 2025.
Copy CitationKids Definition
infiltrate
verb
in·fil·trate
in-ˈfil-ˌtrāt
ˈin-(ˌ)fil-
ˈin-(ˌ)fil-
infiltrated; infiltrating
1
: to pass into or through by filtering
2
: to enter or become established gradually or secretly
Medical Definition
infiltrate
1 of 2 verb
in·fil·trate
in-ˈfil-ˌtrāt
ˈin-(ˌ)
ˈin-(ˌ)
infiltrated; infiltrating
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
: 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
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