hillbilly vs bushwhacker

hillbilly and bushwhacker both are nouns.

Word	Noun	Adjective	Verb	Adverb
hillbilly	Yes	No	No	No
bushwhacker	Yes	No	No	No

As nouns, hillbilly and bushwhacker are synonyms defined as:

hillbilly and bushwhacker: a disparaging term for an unsophisticated person

hillbilly (noun)	bushwhacker (noun)
a disparaging term for an unsophisticated person	a disparaging term for an unsophisticated person
	a Confederate guerrilla during the American Civil War