VIRULENCE
virulence, virulency
(noun) extreme hostility; “the virulence of the malicious old man”
virulence, virulency
(noun) extreme harmfulness (as the capacity of a microorganism to cause disease); “the virulence of the plague”
Source: WordNet® 3.1
Etymology
Noun
virulence (countable and uncountable, plural virulences)
The state of being virulent.
A measure of how virulent a thing is.
Source: Wiktionary
Vir"u*lence, Vir"u*len*cy, n. Etym: [Cf. F. virulence, L. virulentia
an offensive odor, a stench.]
1. The quality or state of being virulent or venomous; poisonousness;
malignancy.
2. Extreme bitterness or malignity of disposition. "Refuted without
satirical virulency." Barrow.
The virulence of one declaimer, or the profundities and sublimities
of the other. I. Taylor.
Source: Webster’s Unabridged Dictionary 1913 Edition