ill will vs unfriendliness

ill will and unfriendliness both are nouns.

Word	Noun	Adjective	Verb	Adverb
ill will	Yes	No	No	No
unfriendliness	Yes	No	No	No

As nouns, unfriendliness is a hypernym of ill will; that is, unfriendliness is a word with a broader meaning than ill will:

ill will (noun)	unfriendliness (noun)
a hostile (very unfriendly) disposition	an unfriendly disposition
the feeling of a hostile person	dislike experienced as an absence of friendliness