Noah Webster's New International Dictionary of the English Language

1. (n.) To generate pus; to become inflamed and suppurate; as, a sore or a wound festers.

2. (n.) To be inflamed; to grow virulent, or malignant; to grow in intensity; to rankle.

3. (v. t.) To cause to fester or rankle.

4. (n.) A small sore which becomes inflamed and discharges corrupt matter; a pustule.

5. (n.) A festering or rankling.