fester

As a verb fester

is to become septic; to become rotten.

As an adjective infectious is

(pathology|of an illness) transmitted from one person to another, usually through the air breathed.

As a verb fester

is to become septic; to become rotten.

As a noun infection is

(pathology) the act or process of infecting.

As verbs the difference between sour and fester

is that sour is (label) to make sour while fester is to become septic; to become rotten.

As an adjective sour

is having an acidic, sharp or tangy taste.

As a noun sour

is the sensation of a sour taste.

As verbs the difference between fester and conceal

is that fester is to become septic; to become rotten while conceal is (lb) to hide something from view or from public knowledge, to try to keep something secret.

As a verb fester

is to become septic; to become rotten.

As a noun muster is

example.

As verbs the difference between fester and distress

is that fester is to become septic; to become rotten while distress is to cause strain or anxiety to someone.

As a noun distress is

(cause of) discomfort.

As verbs the difference between fester and ulcerate

is that fester is to become septic; to become rotten while ulcerate is (medicine|transitive) to cause an ulcer to develop.

As an adjective ulcerate is

(palynology|of a pollen grain) having an ulcus, a rounded pore-like aperture, at one or both poles.

As verbs the difference between stagnate and fester

is that stagnate is to cease motion, activity, or progress: while fester is to become septic; to become rotten.

As a verb fester

is to become septic; to become rotten.

As an adjective purulent is

(medicine) consisting of pus, or matter; partaking of the nature of pus; attended with suppuration; as, purulent inflammation.