fighter vs defender

fighter and defender both are nouns.

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

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

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

Other hypernyms of fighter include guardian, protector, shielder.

fighter (noun)	defender (noun)
a high-speed military or naval airplane designed to destroy enemy aircraft in the air	a person who cares for persons or property
someone who fights (or is fighting)	a fighter who holds out against attack
someone who fights for a cause