Dictionary.com
Thesaurus.com
Synonyms

infestation

American  
[in-fe-stey-shuhn] / ˌɪn fɛˈsteɪ ʃən /

noun

  1. the act of infesting; state of being infested.

  2. a harassing or troublesome invasion.

    an infestation of ants.


Other Word Forms

  • reinfestation noun

Etymology

Origin of infestation

1375–1425; late Middle English infestacio ( u ) n < Late Latin infestātiōn- (stem of infestātiō ). See infest, -ation

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The agency also stated that the infestation hadn’t yet penetrated farther north than Oaxaca and Veracruz, 700 miles from the U.S. border.

From Los Angeles Times • Nov. 19, 2025

Its ascendance has contributed to the population decline of various native ladybug species—and more Americans associating ladybugs with infestation and invasion.

From The Wall Street Journal • Nov. 16, 2025

Investors are spotting credit “cockroaches” in the financial system, sparking worries about a broader infestation.

From MarketWatch • Nov. 6, 2025

Fears that Jamie Dimon’s credit “cockroaches” were turning into a bigger infestation gripped markets on Thursday, sending volatility higher and stocks lower.

From Barron's • Oct. 16, 2025

A mild infestation gives trees and shrubbery a mottled or salt-and-pepper appearance; with a heavy mite population, foliage turns yellow and falls.

From "Silent Spring" by Rachel Carson