falsify vs falsifier

falsify is not a noun while falsifier is a noun.

Word	Noun	Adjective	Verb	Adverb
falsify	No	No	Yes	No
falsifier	Yes	No	No	No

falsify (noun)	falsifier (noun)
	someone who falsifies

falsify (verb)	falsifier (verb)
falsify knowingly
insert words into texts, often falsifying it thereby
prove false
make false by mutilation or addition; as of a message or story
tamper, with the purpose of deception