smut

(noun) a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink. Synonyms: carbon black, lampblack, soot, crock.

(noun) destructive diseases of plants (especially cereal grasses) caused by fungi that produce black powdery masses of spores.

(noun) any fungus of the order Ustilaginales. Synonyms: smut fungus.

(noun) an offensive or indecent word or phrase. Synonyms: obscenity, vulgarism, filth, dirty word.

(noun) creative activity (writing or pictures or films etc.) of no literary or artistic value other than to stimulate sexual desire. Synonyms: pornography, porno, porn, erotica.

(verb) make obscene. Example: "This line in the play smuts the entire act."

(verb) stain with a dirty substance, such as soot.

(verb) become affected with smut. Example: "The corn smutted and could not be eaten."

(verb) affect with smut or mildew, as of a crop such as corn.