do it vs filth

do it is not a noun while filth is a noun.

Word	Noun	Adjective	Verb	Adverb
do it	No	No	Yes	No
filth	Yes	No	No	No

do it (noun)	filth (noun)
	an offensive or indecent word or phrase
	a state characterized by foul or disgusting dirt and refuse
	anything regarded as making something unclean
	any substance considered disgustingly foul or unpleasant

do it (verb)	filth (verb)
have sexual intercourse with