smut vs do it

smut is a noun but do it is not a noun.

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

smut (noun)	do it (noun)
creative activity (writing or pictures or films etc.) of no literary or artistic value other than to stimulate sexual desire
an offensive or indecent word or phrase
any fungus of the order Ustilaginales
destructive diseases of plants (especially cereal grasses) caused by fungi that produce black powdery masses of spores
a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink

smut (verb)	do it (verb)
affect with smut or mildew, as of a crop such as corn	have sexual intercourse with
stain with a dirty substance, such as soot
become affected with smut
make obscene