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Synonyms

pest

1 American  
[pest] / pɛst /

noun

  1. an annoying or troublesome person, animal, or thing; nuisance.

    Synonyms:
    annoyance

  2. an insect or other small animal that harms or destroys garden plants, trees, etc.

  3. a deadly epidemic disease, especially a plague; pestilence.

    Synonyms:
    epidemic, scourge, pandemic
Pest 2 American  
[pest, pesht] / pɛst, pɛʃt /

noun

  1. Budapest

pest British  
/ pɛst /

noun

  1. a person or thing that annoys, esp by imposing itself when it is not wanted; nuisance

    1. any organism that damages crops, injures or irritates livestock or man, or reduces the fertility of land

    2. ( as modifier )

      pest control

  3. rare an epidemic disease or pestilence

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • de-pest verb (used with object)

Etymology

Origin of pest

First recorded in 1545–55, pest is from the Latin word pestis plague

Explanation

A pest is something or someone that bugs you. That annoying mosquito that keeps you up at night is a pest, and so is that younger brother who wants to control the TV remote. An unwanted, bothersome person is a pest — and so is an unwanted, bothersome bug. In fact, the "destructive or harmful insect" definition came before "annoying person," following the "plague or pestilence" meaning of pest. The Latin root is pestis, "deadly contagious disease." During the Late Middle Ages, when the bubonic plague killed a third of all humans, it was commonly known as "the pest."

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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.

We have to get access to units occasionally for pest control and I’m always astonished with what’s inside.

From The Wall Street Journal • Apr. 22, 2026

To help Californians rid the state of the pest, the U.S.

From Los Angeles Times • Apr. 10, 2026

They are widely seen as a pest on agricultural land because their tunnelling can damage the root systems of crops and pasture and the molehills can cause damage to machinery.

From BBC • Mar. 22, 2026

The researchers believe their findings could lead to more effective pest control strategies.

From Science Daily • Mar. 22, 2026

In the Belgian Congo and Uganda the results of heavy applications of DDT against an insect pest of the coffee bush were almost “catastrophic.”

From "Silent Spring" by Rachel Carson

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.