grappler vs belligerent

grappler and belligerent both are nouns.

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

As nouns, belligerent is a hypernym of grappler; that is, belligerent is a word with a broader meaning than grappler:

Other hypernyms of grappler include battler, combatant, fighter, scrapper.

grappler (noun)	belligerent (noun)
a tool consisting of several hooks for grasping and holding; often thrown with a rope	someone who fights (or is fighting)
combatant who tries to throw opponent to the ground

grappler (adjective)	belligerent (adjective)
	characteristic of an enemy or one eager to fight
	engaged in war