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
While a wallpaper photographed by Calle was turned into a key black-and-white print in the collection, with small bellflowers blossoming on shirts and pants, a flavor for Orientalism infiltrated Rizza’s designs, inspired by some of Calle’s snapshots.
—
Sandra Salibian, Footwear News, 3 Oct. 2025
This cannot be accomplished without infiltrating and taking over the PLO, something Hamas has never managed to do.
—Hussein Ibish, The Atlantic, 1 Oct. 2025
Alex’s reporting on the lobbyists infiltrating the climate summit ticked off an oil exec whose company takes out a lot of advertising on UBN.
—Kimberly Roots, TVLine, 1 Oct. 2025
Where Lil Boosie and Kevin Gates are hometown heroes, two artists who are direct ancestors for YoungBoy’s style, YoungBoy is more notorious, fodder for the gossip shows and the minor podcasts that infiltrate their way onto your timeline.
—Jayson Buford, Rolling Stone, 30 Sep. 2025
See All Example Sentences for infiltrate
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Sandra Salibian, Footwear News, 3 Oct. 2025
This cannot be accomplished without infiltrating and taking over the PLO, something Hamas has never managed to do.
—Hussein Ibish, The Atlantic, 1 Oct. 2025
Alex’s reporting on the lobbyists infiltrating the climate summit ticked off an oil exec whose company takes out a lot of advertising on UBN.
—Kimberly Roots, TVLine, 1 Oct. 2025
Where Lil Boosie and Kevin Gates are hometown heroes, two artists who are direct ancestors for YoungBoy’s style, YoungBoy is more notorious, fodder for the gossip shows and the minor podcasts that infiltrate their way onto your timeline.
—Jayson Buford, Rolling Stone, 30 Sep. 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 6 Oct. 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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