harrier vs aggressor

harrier and aggressor both are nouns.

Word	Noun	Adjective	Verb	Adverb
harrier	Yes	No	No	No
aggressor	Yes	No	No	No

As nouns, aggressor is a hypernym of harrier; that is, aggressor is a word with a broader meaning than harrier:

Other hypernyms of harrier include assailant, assaulter, attacker.

harrier (noun)	aggressor (noun)
hawks that hunt over meadows and marshes and prey on small terrestrial animals	someone who attacks
a hound that resembles a foxhound but is smaller; used to hunt rabbits	a confident assertive person who acts as instigator
a persistent attacker