separationist vs advocator

separationist and advocator both are nouns.

Word	Noun	Adjective	Verb	Adverb
separationist	Yes	No	No	No
advocator	Yes	No	No	No

As nouns, advocator is a hypernym of separationist; that is, advocator is a word with a broader meaning than separationist:

separationist: an advocate of secession or separation from a larger group (such as an established church or a national union)
advocator: a person who pleads for a cause or propounds an idea

Other hypernyms of separationist include advocate, exponent, proponent.

separationist (noun)	advocator (noun)
an advocate of secession or separation from a larger group (such as an established church or a national union)	a person who pleads for a cause or propounds an idea