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- cf. 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

In April, the government shared their update of the Women's Health Strategy, when Health Secretary Wes Streeting said they wanted to "dismantle the culture and ingrained behaviours that allow medical misogyny to fester and grow".

From BBC • May 11, 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

And over six seasons, the series examined the under-explored territory that lay between two world wars—a kind of historical trench in which all manner of skullduggery could fester and bloom.

From The Wall Street Journal • Mar. 19, 2026

At the same time, those provisions do not align with other features of the student-loan system that can allow the debt to fester for decades.

From MarketWatch • Dec. 19, 2025

Shattered legs may heal in time, but some betrayals fester and poison the soul.

From "A Game of Thrones" by George R.R. Martin

Related Words

• smolder