separatist vs proponent

separatist and proponent both are nouns.

Word	Noun	Adjective	Verb	Adverb
separatist	Yes	Yes	No	No
proponent	Yes	No	No	No

As nouns, proponent is a hypernym of separatist; that is, proponent is a word with a broader meaning than separatist:

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

Other hypernyms of separatist include advocate, advocator, exponent.

separatist (noun)	proponent (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

separatist (adjective)	proponent (adjective)
having separated or advocating separation from another entity or policy or attitude