fester
verbUK /ˈfestə/
US /ˈfestər/
A cut or sore gets worse and full of pus because it is not cleaned.
The small cut on his knee began to fester after he played in the mud.
RELATED WORDS
OTHER MEANINGS
2. To become more bitter and angry over time.
His resentment festered for years after the argument.
3. To rot or decay with a bad smell.
The old food festered in the warm garbage bin.
4. To grow worse and more harmful if left alone.
The problem festered because nobody wanted to talk about it.