stalwart vs protagonist

stalwart and protagonist both are nouns.

Word	Noun	Adjective	Verb	Adverb
stalwart	Yes	Yes	No	No
protagonist	Yes	No	No	No

As nouns, protagonist is a hypernym of stalwart; that is, protagonist is a word with a broader meaning than stalwart:

stalwart: a person who is loyal to their allegiance (especially in times of revolt)
protagonist: a person who backs a politician or a team etc.

Other hypernyms of stalwart include admirer, booster, champion, friend, supporter.

stalwart (noun)	protagonist (noun)
a person who is loyal to their allegiance (especially in times of revolt)	a person who backs a politician or a team etc.
	the principal character in a work of fiction

stalwart (adjective)	protagonist (adjective)
used especially of persons
dependable
having rugged physical strength; inured to fatigue or hardships