republican vs advocate

republican and advocate both are nouns.

Word	Noun	Adjective	Verb	Adverb
republican	Yes	Yes	No	No
advocate	Yes	No	Yes	No

As nouns, advocate is a hypernym of republican; that is, advocate is a word with a broader meaning than republican:

Other hypernyms of republican include advocator, exponent, proponent.

republican (noun)	advocate (noun)
an advocate of a republic (usually in opposition to a monarchy)	a person who pleads for a cause or propounds an idea
	a lawyer who pleads cases in court

republican (adjective)	advocate (adjective)
relating to or belonging to the Republican Party
having the supreme power lying in the body of citizens entitled to vote for officers and representatives responsible to them or characteristic of such government

republican (verb)	advocate (verb)
	push for something
	speak, plead, or argue in favor of