1. (of a wound or sore) become septic; suppurate: "I developed a tropical sore that festered badly"Similarsuppuratebecome septicform pussecrete pusdischargerunweepoozecome to a headtechnical:maturatebe purulentrare:rankleapostemate
▪ (of a negative feeling or a problem) become worse or more intense, especially through long-term neglect or indifference: "below the surface, the old antagonisms festered"Similarranklechafegnaw (at one's mind)eat away at one's mindfermentbrewsmouldercause bitternesscause resentmentcause vexationcause annoyance
▪ (of a person) deteriorate physically and mentally in isolated inactivity:"remand prisoners are left to fester in our jails while they wait for trial"
Word Originlate Middle English: from the rare word fester ‘fistula’, later ‘festering sore’, or Old French festrir (verb), both from Old French festre (noun), from Latin fistula ‘pipe, reed, fistula’.