separationist vs exponent

separationist and exponent both are nouns.

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

As nouns, exponent is a hypernym of separationist; that is, exponent 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)
exponent: a person who pleads for a cause or propounds an idea

Other hypernyms of separationist include advocate, advocator, proponent.

separationist (noun)	exponent (noun)
an advocate of secession or separation from a larger group (such as an established church or a national union)	a mathematical notation indicating the number of times a quantity is multiplied by itself
	a person who pleads for a cause or propounds an idea
	someone who expounds and interprets or explains