fester
v.v. to become infected and start to rot. It is often used to describe a wound or a situation that is getting worse over time.
v. to become infected and begin to decay; to undergo putrefaction. Often used figuratively to describe the gradual deterioration of a situation or relationship.
The wound began to fester after he stopped cleaning it.
If left unaddressed, the small disagreement between the neighbors will only fester and turn into a full-blown feud.
The neglected garden was a perfect environment for the old cuts to fester, eventually leading to a systemic infection that required immediate medical intervention.
Inherited from Middle English festre, festur, borrowed from Old French festre (cognate with Italian fistola, Occitan fistola, Spanish fístula), from Latin fistula. The verb is derived from the noun, while the “condition of something that festers” noun sense is derived from the verb. Doublet of fistula.