rebut vs rebutter

rebut is not a noun while rebutter is a noun.

Word	Noun	Adjective	Verb	Adverb
rebut	No	No	Yes	No
rebutter	Yes	No	No	No

rebut (noun)	rebutter (noun)
	(law) a pleading by the defendant in reply to a plaintiff's surrejoinder
	a debater who refutes or disproves by offering contrary evidence or argument

rebut (verb)	rebutter (verb)
prove to be false or incorrect
overthrow by argument, evidence, or proof