infest

verb

in·​fest in-ˈfest How to pronounce infest (audio)
infested; infesting; infests
Synonyms of infestnext

transitive verb

1
: to spread or swarm in or over in a troublesome manner
shark-infested waters
2
: to live in or on as a parasite
infestant
in-ˈfe-stənt How to pronounce infest (audio)
noun
infestation
ˌin-ˌfe-ˈstā-shən How to pronounce infest (audio)
noun
infester
in-ˈfe-stər How to pronounce infest (audio)
noun

Synonyms of 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The paths through the bush are infested with these ticks, as are many back yards. — Burkhard Bilger, New Yorker, 29 June 2026 Remove the stems that are heavily infested. — Michelle Mastro, Martha Stewart, 24 June 2026 Hives can become infested with Varroa mites, which infect the bees with flight-robbing viruses. — Joan Morris, Mercury News, 29 June 2026 When left unattended in a basement for a prolonged period, things are bound to acquire mold and mildew or become infested with unwelcome guests. — Mary Cornetta, Better Homes & Gardens, 26 June 2026 See All Example Sentences for infest

Word History

Etymology

French infester, from Latin infestare, from infestus hostile

First Known Use

1602, in the meaning defined at sense 1

Time Traveler
The first known use of infest was in 1602

Rhymes for infest

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Browse Nearby Words

infertility
infest
infester
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Cite this Entry

“Infest.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infest. Accessed 7 Jul. 2026.

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Kids Definition

infest

verb
in·​fest in-ˈfest How to pronounce infest (audio)
1
: to spread or swarm in or over in a troublesome manner
a neighborhood infested with crime
shark-infested waters
2
: to live in or on as a parasite
horses infested with worms
infestation
ˌin-ˌfes-ˈtā-shən How to pronounce infest (audio)
noun

Medical Definition

infest

transitive verb
in·​fest in-ˈfest How to pronounce infest (audio)
: to live in or on as a parasite
the flea that infests cats
horses infested with worms
compare infect

More from Merriam-Webster on infest

Nglish: Translation of infest for Spanish Speakers

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