a black colloidal substance consisting wholly or principally of amorphous carbon and used to make pigments and ink
"The old printer was clogged because someone had spilled soot, the raw smut needed for making charcoal inks, all over the gears."
destructive diseases of plants (especially cereal grasses) caused by fungi that produce black powdery masses of spores
"The late summer rains brought a devastating smut infection to the wheat fields, leaving rows covered in black fungal powder."
any fungus of the order Ustilaginales
"The farmer inspected the wheat fields closely to see if they were infected by smut, a type of fungal disease that turns the grain heads black."
an offensive or indecent word or phrase
"The teacher asked everyone to stop whispering smut while she was trying to teach the lesson."
creative activity (writing or pictures or films etc.) of no literary or artistic value other than to stimulate sexual desire
"The movie was banned from local theaters because it was just smut designed solely to arouse viewers."
Soot.
"The old chimney was covered in a thick layer of smut from years of burning coal."
stain with a dirty substance, such as soot
"The old chimney sweep accidentally smudged his white apron with black soot while climbing down from the roof."
affect with smut or mildew, as of a crop such as corn
"The heavy rains left the entire cornfield to rot from the smut that had taken hold weeks ago."
To stain (or be stained) with soot or other dirt.
"The chimney sweep's hands were covered in black smut after hours of scrubbing the brick flue."