Bitterness is a related term of virulence.
As nouns the difference between bitterness and virulence
is that bitterness is the quality of having a bitter taste while virulence is the state of being virulent.
bitterness
English
Noun
the quality of having a bitter taste
the quality of feeling bitter; acrimony, resentment
Synonyms
* (quality of being bitter in taste) acerbicness, acridity, acridness
* (quality of feeling bitter) acrimony, gall, rancor/rancour, resentment
virulence
English
Noun
the state of being virulent
a measure of how virulent a thing is