infiltrate

verb
in·​fil·​trate | \ in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) , ˈin-(ˌ)fil- How to pronounce infiltrate (audio) \
infiltrated; infiltrating

Definition of infiltrate

transitive verb

1 : to cause (something, such as a liquid) to permeate something by penetrating its pores or interstices
2 : to pass into or through (a substance) by filtering or permeating
3 : to pass (troops) singly or in small groups through gaps in the enemy line
4 : to enter or become established in gradually or unobtrusively usually for subversive purposes the intelligence staff had been infiltrated by spies

intransitive verb

: to enter, permeate, or pass through a substance or area by filtering or by insinuating gradually

Keep scrolling for more

Other Words from infiltrate

infiltrate noun
infiltration \ ˌin-​(ˌ)fil-​ˈtrā-​shən How to pronounce infiltration (audio) \ noun
infiltrative \ ˈin-​(ˌ)fil-​ˌtrā-​tiv How to pronounce infiltrative (audio) , in-​ˈfil-​trə-​ \ adjective
infiltrator \ in-​ˈfil-​ˌtrā-​tər How to pronounce infiltrator (audio) , ˈin-​(ˌ)fil-​ How to pronounce infiltrator (audio) \ noun

Synonyms for infiltrate

Synonyms

insinuate, slip, sneak, wind, work in, worm, wriggle

Visit the Thesaurus for More 

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.
See More

Recent Examples on the Web

He's emerged as a significant character over the past few years, befriending Steve Harrington (Joe Keery), infiltrating a secret Russian facility and, most importantly, getting a girlfriend. Kathryn Lindsay, refinery29.com, "Someone Found The Answer To Dustin's Biggest Mystery In Season 3 Of Stranger Things," 5 July 2019 Rum infiltrates sorbet, too, including one stained red from sorrel, the flowers brewed with cinnamon and cloves. Ligaya Mishan, New York Times, "Celebrating America, Scoop by Frosty Scoop," 2 July 2019 Though Russia infiltrated voting networks in 2016, there is no evidence any machines were tampered with or votes changed. The Washington Post, Twin Cities, "Other voices: How to prevent another Russian attack," 13 June 2019 But injuries infiltrated a trio of right-handers: Clevinger went down. Marc Bona, cleveland.com, "Indians’ Mike Clevinger looks strong in rehab start in Akron (video)," 11 June 2019 Any more water on top of that wouldn’t infiltrate the soil and instead would accumulate at the surface. Umair Irfan, Vox, "The severe floods soaking the Midwest and Southeast are not letting up," 11 June 2019 Book 19’s purpose is to escalate tensions; Odysseus has infiltrated his own house and is stockpiling weapons to slaughter the suitors the next day. Anne Carson, Harper's magazine, "From a manuscript in progress. Carson’s collection of performance pieces," 10 June 2019 In the case of the Anthem data breach of 2014, hackers infiltrated the health insurance company’s servers to access social security numbers, addresses and other financial information from nearly 80 million people. Jared Weber, USA TODAY, "Medical data stolen in Quest breach makes patients very vulnerable, experts say," 6 June 2019 Record-scratch time: a troop of roughly 20 armed guards somehow infiltrates one of Monarch's ultra-classified mega-monster lairs (and many others as the film proceeds) with little more than semi-automatic rifles. Sam Machkovech, Ars Technica, "Godzilla: King of the Monsters," 31 May 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infiltrate.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of infiltrate

1758, in the meaning defined at transitive sense 1

Keep scrolling for more

Learn More about infiltrate

Statistics for infiltrate

Last Updated

9 Jul 2019

Look-up Popularity

Time Traveler for infiltrate

The first known use of infiltrate was in 1758

See more words from the same year

Keep scrolling for more

More Definitions for infiltrate

infiltrate

verb

English Language Learners Definition of infiltrate

: to secretly enter or join (something, such as a group or an organization) in order to get information or do harm
: to cause (someone) to secretly enter or join a group, organization, etc.
technical : to pass into or through (something)

infiltrate

verb
in·​fil·​trate | \ in-ˈfil-ˌtrāt How to pronounce infiltrate (audio) , ˈin-(ˌ) How to pronounce infiltrate (audio) \
infiltrated; infiltrating

Medical Definition of infiltrate

 (Entry 1 of 2)

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

noun

Medical Definition of infiltrate (Entry 2 of 2)

: 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

Keep scrolling for more

Comments on infiltrate

What made you want to look up infiltrate? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

something desired as essential

Get Word of the Day daily email!

Test Your Vocabulary

What's that Smell?! Quiz

  • wide eyed dog smelling rose
  • Someone who is hircine smells like a:
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!