English Reference

Word

infestation

Phoneticsin·fes·ta·tion

US/ˌɪnˈfɛsˈteɪʃən/

UK/ɪnfɛstˈeɪʃən/

Definition

n. the presence of a large number of pests, like insects or rats, in a place where they cause damage or health problems.

n. the state of being invaded or overrun by pests or parasites in numbers large enough to be harmful or obnoxious.

Examples

“The landlord had to deal with a serious ant infestation.”

“Health inspectors closed the restaurant immediately after discovering a severe rodent infestation in the dry storage area.”

“Agricultural experts warned that the locust infestation could devastate the region's wheat crops if containment measures were not implemented before the next breeding cycle.”

Examples

simple

“The landlord had to deal with a serious ant infestation.”

contextual

“Health inspectors closed the restaurant immediately after discovering a severe rodent infestation in the dry storage area.”

complex

“Agricultural experts warned that the locust infestation could devastate the region's wheat crops if containment measures were not implemented before the next breeding cycle.”

Usage

Uncountable when referring to the general state of being infested; countable when referring to a specific instance or occurrence.

Real-World Examples

Common in science writing

“For the past six years – counter to the far-right “life-of-luxury” narrative – Diane has reported on life inside these hotels: rat infestations and food so abysmal it causes nutritional deficiencies.”
The Guardian · 13 Aug 2026
“H13 triggers local cell death, cell-wall reinforcement, and larva-toxic molecules, depriving larvae of nutrients and limiting infestation.”
Phys.org · 14 Aug 2026

Etymology

From Middle French infestation, from Late Latin infestatio. Morphologically infest + -ation.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

englishreference.com/q/infestation

English Reference