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
Use your hands to agitate the cushion covers so the soapy water infiltrates the fabric.
—
Patricia Shannon, Southern Living, 13 Aug. 2025
On Monday, Russian sabotage and reconnaissance groups were infiltrating areas near northwest of Pokrovsk in the Donetsk region near where Russian forces likely have made advances, according to the Institute for the Study of War.
—Brendan Cole, MSNBC Newsweek, 12 Aug. 2025
Rebecca has infiltrated a Seoul hotel in order to kill a high-ranking Russian official, while David has done the same at a nearby karaoke bar in hopes of intercepting her.
—Angie Han, HollywoodReporter, 12 Aug. 2025
From fake bands to artificially generated songs, AI is increasingly infiltrating the music world.
—David Browne, Rolling Stone, 11 Aug. 2025
See All Example Sentences for infiltrate
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Patricia Shannon, Southern Living, 13 Aug. 2025
On Monday, Russian sabotage and reconnaissance groups were infiltrating areas near northwest of Pokrovsk in the Donetsk region near where Russian forces likely have made advances, according to the Institute for the Study of War.
—Brendan Cole, MSNBC Newsweek, 12 Aug. 2025
Rebecca has infiltrated a Seoul hotel in order to kill a high-ranking Russian official, while David has done the same at a nearby karaoke bar in hopes of intercepting her.
—Angie Han, HollywoodReporter, 12 Aug. 2025
From fake bands to artificially generated songs, AI is increasingly infiltrating the music world.
—David Browne, Rolling Stone, 11 Aug. 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 20 Aug. 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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