aggression vs unfriendliness

aggression and unfriendliness both are nouns.

Word	Noun	Adjective	Verb	Adverb
aggression	Yes	No	No	No
unfriendliness	Yes	No	No	No

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

aggression (noun)	unfriendliness (noun)
violent action that is hostile and usually unprovoked	an unfriendly disposition
deliberately unfriendly behavior	dislike experienced as an absence of friendliness
the act of initiating hostilities
a disposition to behave aggressively
a feeling of hostility that arouses thoughts of attack