From Longman Dictionary of Contemporary Englishfesterfes‧ter /ˈfestə $ -ər/ verb [intransitive] 1 INCREASE IN ACTIVITY, FEELINGS ETCUNPLEASANTif an unpleasant feeling or problem festers, it gets worse because it has not been dealt with The dispute can be traced back to resentments which have festered for centuries.2 MIILLNESS/DISEASEif a wound festers, it becomes infected festering sores3 DECAYif rubbish or dirty objects fester, they decay and smell bad→ See Verb table
Examples from the Corpus
fester• Deep in the interstices of daily life, no doubt, frustrations gnawed at him and resentments festered.• Our eyes joined across the metres of festering carpet.• The insider-trading case also revisits a long festering controversy.• Gone too are sources of social difficulty, human reminders of festering disagreements and failed love affairs.• The school toilet was a festering, diseased shed at the ravine's edge.• Disputes between environmentalists and loggers have been festering for decades.• The animal parts were allowed to fester in the hot sun.• A festering inflammation on his foot kept him from joining the Capuchin order.• It was clear to everyone that it would only aggravate the festering wound.Origin fester (1300-1400) Old French festre “sore hole in flesh”, from Latin fistula 