1. To cause to fester.

2. To corrupt; to suppurate; to rankle to grow more virulent.

3. An inflamed tumour containing purulent matter.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• certer,
• ofster,
• fasterr,
• foser,
• fosterd,
• fested,
• freater,
• feauter,
• faaster,
• fasther,
• fafter,
• jestor,
• fastar,
• festure,
• guester,
• gester,
• desiter,
• futer,
• featur,
• seester

• jester,
• foster,
• Feaster,
• faster,
• festering,
• nester,
• fister,
• pester.

The adverb for the word "fester" is "festeringly".

The adjective form of the word "fester" is "festering".

The plural of the "fester" can be the "festers".

The singular of the "fester" can be the "fester".