virulency vs virulence

virulency and virulence both are nouns.

Word	Noun	Adjective	Verb	Adverb
virulency	Yes	No	No	No
virulence	Yes	No	No	No

As nouns, virulency and virulence are synonyms defined as:

virulency and virulence: extreme harmfulness (as the capacity of a microorganism to cause disease)

As nouns, virulency and virulence are synonyms defined as:

virulency (noun)	virulence (noun)
extreme harmfulness (as the capacity of a microorganism to cause disease)	extreme harmfulness (as the capacity of a microorganism to cause disease)
extreme hostility	extreme hostility