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
The past few weeks have felt like a Cold War thriller in which an enemy agent somehow infiltrates the top of the United States government.
—
David Frum, The Atlantic, 12 Mar. 2025
The ending, though, doesn't see Kimmie crippling the Bellaire dynasty so much as infiltrating it.
—Randall Colburn, EW.com, 11 Mar. 2025
If ransomware infiltrates a segment containing noncritical systems, the damage remains localized.
—Sameer Malhotra, Forbes, 10 Mar. 2025
Italian food products and cuisine have infiltrated just about every corner of the globe, but there’s no comparison to trying classic Italian recipes at their source—and there’s so much more than pizza, pasta, and gelato.
—Laura Itzkowitz, Travel + Leisure, 9 Mar. 2025
See All Example Sentences for infiltrate
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David Frum, The Atlantic, 12 Mar. 2025
The ending, though, doesn't see Kimmie crippling the Bellaire dynasty so much as infiltrating it.
—Randall Colburn, EW.com, 11 Mar. 2025
If ransomware infiltrates a segment containing noncritical systems, the damage remains localized.
—Sameer Malhotra, Forbes, 10 Mar. 2025
Italian food products and cuisine have infiltrated just about every corner of the globe, but there’s no comparison to trying classic Italian recipes at their source—and there’s so much more than pizza, pasta, and gelato.
—Laura Itzkowitz, Travel + Leisure, 9 Mar. 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 19 Mar. 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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