supplanter vs usurper

supplanter and usurper both are nouns.

Word	Noun	Adjective	Verb	Adverb
supplanter	Yes	No	No	No
usurper	Yes	No	No	No

As nouns, supplanter and usurper are synonyms defined as:

supplanter and usurper: one who wrongfully or illegally seizes and holds the place of another

supplanter (noun)	usurper (noun)
one who wrongfully or illegally seizes and holds the place of another	one who wrongfully or illegally seizes and holds the place of another