aggression vs combat

aggression and combat both are nouns.

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

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

Other hypernyms of aggression include armed combat.

aggression (noun)	combat (noun)
violent action that is hostile and usually unprovoked	an engagement fought between two military forces
deliberately unfriendly behavior	the act of fighting; any contest or struggle
the act of initiating hostilities
a disposition to behave aggressively
a feeling of hostility that arouses thoughts of attack

aggression (verb)	combat (verb)
	battle or contend against in or as if in a battle