aggressive vs belligerent

aggressive is not a noun while belligerent is a noun.

Word	Noun	Adjective	Verb	Adverb
aggressive	No	Yes	No	No
belligerent	Yes	Yes	No	No

As adjectives, aggressive and belligerent are synonyms defined as:

aggressive and belligerent: characteristic of an enemy or one eager to fight

aggressive (noun)	belligerent (noun)
	someone who fights (or is fighting)

aggressive (adjective)	belligerent (adjective)
having or showing determination and energetic pursuit of your ends	characteristic of an enemy or one eager to fight
characteristic of an enemy or one eager to fight	engaged in war
tending to spread quickly