seconder vs protagonist

seconder and protagonist both are nouns.

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

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

seconder: someone who endorses a motion or petition as a necessary preliminary to a discussion or vote
protagonist: a person who backs a politician or a team etc.

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

seconder (noun)	protagonist (noun)
someone who endorses a motion or petition as a necessary preliminary to a discussion or vote	a person who backs a politician or a team etc.
	the principal character in a work of fiction