infest

verb

in·​fest in-ˈfest 

infested; infesting; infests

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

infestant

in-ˈfe-stənt 

noun

infestation

ˌin-ˌfe-ˈstā-shən 

noun

infester

in-ˈfe-stər 

noun

Synonyms

• overrun

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

Singh says bed bugs could infest the clothes inside of your luggage. —Ashley J. Dimella Fox News, Fox News, 14 Jan. 2025

How did Eagle get infested? Conspiracy theorists, er, experts pointed to out-of-staters moving into town. —Michael Deeds, Idaho Statesman, 10 Jan. 2025

The 2,000 trees arrived, but unfortunately were found to be infested with pests and destroyed. —Jessica Farthing, Southern Living, 2 Jan. 2025

Looking down on his realm — a city infested by corruption scandals multiplying like mold spores — Carollo embraced the applause. —Linda Robertson, Miami Herald, 8 Jan. 2025

Word History

Etymology

French infester, from Latin infestare, from infestus hostile

First Known Use

1602, in the meaning defined at sense 1

Kids Definition

infest

verb

in·​fest in-ˈfest 

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 

noun

Medical Definition

infest

transitive verb

in·​fest in-ˈfest 

: to live in or on as a parasite

the flea that infests cats

horses infested with worms

compare infect