Answer: festers

AnswerCrossword Clue
FESTERSRots
FESTERSRankles
FESTERSIncreases, as seething
FESTERSIrritates
FESTERSCauses increasing irritation
FESTERSWorsens over time
FESTERSBecomes more and more intense, as anger
FESTERSGrows increasingly more irksome
festersto form pus
festersFESTER, to generate pus
festersto rankle, as bitterness