guardian vs defender

guardian and defender both are nouns.

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

As nouns, guardian and defender are synonyms defined as:

Other synonyms of guardian include protector, shielder.

guardian (noun)	defender (noun)
a person who cares for persons or property	a person who cares for persons or property
	a fighter who holds out against attack