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.
Authorities are investigating after human remains at a Chicago funeral home were allegedly found decaying in an unrefrigerated area infested with rodents. — Jeanine Santucci, USA Today, 8 Aug. 2026 Felix Molina has noticed the difference at a local park that used to be rat-infested. — Dave Carlin, CBS News, 6 Aug. 2026 By the same logic, to write anything at all is to go into the locked room of your potential and realise that the roof is leaking, there’s damp in the walls and the furniture is infested with woodworm. — Literary Hub, 5 Aug. 2026 Luca explained that these patches had been infested by pine bark beetles, notorious evergreen-killers that feed on stressed or weakened conifers. — Vann R. Newkirk Ii, The Atlantic, 28 July 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

See All Rhymes for infest

Browse Nearby Words

infertility
infest
infester
See all Nearby Words

Cite this Entry

“Infest.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infest. Accessed 11 Aug. 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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