hostility vs virulency

hostility and virulency both are nouns.

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

As nouns, virulency is a hyponym of hostility; that is, virulency is a word with a more specific, narrower meaning than hostility:

Other hyponyms of hostility include virulence.

hostility (noun)	virulency (noun)
violent action that is hostile and usually unprovoked	extreme harmfulness (as the capacity of a microorganism to cause disease)
a hostile (very unfriendly) disposition	extreme hostility
the feeling of a hostile person
a state of deep-seated ill-will