fester

His wounds festered for days before he got medical attention.他的伤口化脓了好几天才得到护理。

a festering sore正在化脓的溃疡

His feelings of resentment have festered for years.这些年来他的怨恨情绪越积越深。

We should deal with these problems now instead of allowing them to fester.我们应当现在就处理这些问题，而不是让它们进一步恶化。