fester

American  

[fes-ter] / ˈfɛs tər /

verb (used without object)

1. to form pus; generate purulent matter; suppurate.

2. to cause ulceration, as a foreign body in the flesh.

3. to putrefy or rot.

4. to rankle, as a feeling of resentment.

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verb (used with object)

1. to cause to rankle.

   Malice festered his spirit.

noun

1. an ulcer; a rankling sore.

2. a small, purulent, superficial sore.

fester British  

/ ˈfɛstə /

verb

1. to form or cause to form pus

2. (intr) to become rotten; decay

3. to become or cause to become bitter, irritated, etc, esp over a long period of time; rankle

   resentment festered his imagination

4. informal (intr) to be idle or inactive

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noun

1. a small ulcer or sore containing pus

Other Word Forms

• unfestered adjective
• unfestering adjective

Etymology

Origin of fester

1350–1400; (noun) Middle English festir, festre < Anglo-French, Old French festre < Latin fistula fistula (for -l- > -r- chapter ); (v.) Middle English festryn, derivative of the noun or < Old French festrir

Explanation

To fester is to grow and spread, not in a good way. When a cut gets infected it starts to fester and smell bad. Emotional wounds stink too, like when you hold on to anger or pain until it starts to fester and explodes. Fester is a verb describing what happens to a wound or a sore that gets worse and has liquid, or pus, oozing out. Infections cause cuts, broken bones, and diseases to fester. Dead bodies can fester too — as they decompose. Things that fester have a decaying odor, and bad feelings can have a decaying effect on friendships and the heart. Letting bitter emotions fester often leads to their getting worse.

Example Sentences

Webb was able to take on some of Hong Kong’s most powerful constituencies and castigate regulatory authorities for letting corporate governance issues fester.

From Barron's • Apr. 7, 2026

Sweeping contentious issues under the rug and relegating them to wanton aggravation is one major way of letting these same topics fester.

From Salon • Apr. 3, 2026

The Jewish community has warned time and again that when hatred is allowed to fester, when it is excused, normalized or mainstreamed, it inevitably leads to violence.

From The Wall Street Journal • Dec. 18, 2025

The company is “kind of letting it fester now,” with the potential for the narrative to drag into next week, he added.

From MarketWatch • Nov. 26, 2025

His father knew every place in the boy where a word would fester.

From "The Red Pony" by John Steinbeck

Related Words

• smolder