objector vs protester

objector and protester both are nouns.

Word	Noun	Adjective	Verb	Adverb
objector	Yes	No	No	No
protester	Yes	No	No	No

As nouns, objector and protester are synonyms defined as:

objector and protester: a person who dissents from some established policy

Other synonyms of objector include contestant, dissenter, dissident.

objector (noun)	protester (noun)
a person who dissents from some established policy	someone who participates in a public display of group feeling
	a person who dissents from some established policy