in·​fest | \ in-ˈfest How to pronounce infest (audio) \
infested; infesting; infests

Definition of infest

transitive verb

1 : to spread or swarm in or over in a troublesome manner a slum infested with crime shark-infested waters
2 : to live in or on as a parasite

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Other Words from infest

infestant \ in-​ˈfe-​stənt How to pronounce infestant (audio) \ noun
infestation \ ˌin-​ˌfe-​ˈstā-​shən How to pronounce infestation (audio) \ noun
infester \ in-​ˈfe-​stər How to pronounce infester (audio) \ noun

Synonyms for infest


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Examples of infest in a Sentence

in desperation, we called in an exterminator because the house was infested with ants
Recent Examples on the Web If resident Canada geese infest the lawns and sidewalks of a local business and the Illinois DNR initiates a cull, Avery will take that goose meat to a pantry. Joe Genzel, Outdoor Life, "The Wild Game State Agencies Confiscate Does Not Go in a Dumpster," 10 Feb. 2020 The impeachment trial result was always a foregone conclusion, given the cancerous infestation of corruption and screeching propaganda that infests the Republican Party. Ryan Cooper, TheWeek, "American democracy is dying," 7 Feb. 2020 Bring it back indoors before nights dip into the 50s, and consider treating with neem oil before bringing it inside to prevent any potential hitchhikers from infesting the rest of your indoor plants. Arricca Elin Sansone, Country Living, "How to Care for a Money Tree," 24 Jan. 2020 Charlotte quickly and quietly became one of the nation’s most important financial hubs, as Amazon facilities began to infest the state’s rural communities and Dollar Trees replaced mom-and-pop groceries. Nick Martin, The New Republic, "The Decade When Republicans Stole the States," 24 Dec. 2019 One was placed in a basement unit that had no heat and was infested with rats and spiders. Maria Perez,, "American farms recruit Mexican veterinarians for jobs as animal scientists — but the real work is milking cows and cleaning pens for low pay," 4 Dec. 2019 Speakers covered topics such as bed bug biology, bed bugs in public spaces and who pays when a rental unit is infested. Julie Washington, cleveland, "Bed bugs don’t transmit disease, but still cause stress: say local conference leaders," 4 Nov. 2019 In For Whom the Bell Tolls, Hemingway’s doomed and dashing hero gets asked by his Spanish Civil War comrades whether our United States could be likewise infested by fascists. Colin Barrett, Harper's magazine, "“Just Keep Going North”," 5 July 2019 One, the opossum, is a tick-eliminating champ, grooming away 96 percent of tick larvae that infest it, a research study says. National Geographic, "Holographic elephants shine new light on tradition—and other innovations," 5 Nov. 2019

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

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First Known Use of infest

1602, in the meaning defined at sense 1

History and Etymology for infest

French infester, from Latin infestare, from infestus hostile

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Time Traveler for infest

Time Traveler

The first known use of infest was in 1602

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Statistics for infest

Last Updated

22 Feb 2020

Cite this Entry

“Infest.” Dictionary, Merriam-Webster, Accessed 30 Mar. 2020.

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More Definitions for infest


How to pronounce infest (audio)

English Language Learners Definition of infest

of something harmful or unwanted : to be in or over (a place, an animal, etc.) in large numbers


in·​fest | \ in-ˈfest How to pronounce infest (audio) \
infested; infesting

Kids Definition of infest

: to spread or swarm in or over in a harmful manner Termites infested the tree.
in·​fest | \ in-ˈfest How to pronounce infest (audio) \

Medical Definition of infest

: to live in or on as a parasite the flea that infests cats horses infested with worms — compare infect

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More from Merriam-Webster on infest

Thesaurus: All synonyms and antonyms for infest

Spanish Central: Translation of infest

Nglish: Translation of infest for Spanish Speakers

Britannica English: Translation of infest for Arabic Speakers

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