smut

A particle of dirt or soot.

A smudge made by soot, smoke, or dirt.

Sexually explicit or prurient language or material, such as books or movies.

Any of various plant diseases, especially of cereal grasses, caused by parasitic fungi chiefly of the class Ustilaginomycetes that form black powdery masses of spores on the affected parts.

A fungus causing such a disease.