grappler vs fighter

grappler and fighter both are nouns.

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

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

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

grappler (noun)	fighter (noun)
a tool consisting of several hooks for grasping and holding; often thrown with a rope	a high-speed military or naval airplane designed to destroy enemy aircraft in the air
combatant who tries to throw opponent to the ground	someone who fights (or is fighting)
	someone who fights for a cause