spokesperson vs advocate

spokesperson and advocate both are nouns.

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

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

Other hypernyms of spokesperson include advocator, exponent, proponent.

spokesperson (noun)	advocate (noun)
an advocate who represents someone else's policy or purpose	a person who pleads for a cause or propounds an idea
	a lawyer who pleads cases in court

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