aggression vs pillaging

aggression and pillaging both are nouns.

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

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

Other hyponyms of aggression include meat grinder, force, violence, pillage, plundering.

aggression (noun)	pillaging (noun)
violent action that is hostile and usually unprovoked	the act of stealing valuable things from a place
deliberately unfriendly behavior
the act of initiating hostilities
a disposition to behave aggressively
a feeling of hostility that arouses thoughts of attack