smut >> smʌt
Definition: [noun] a small flake of soot or other dirt or a mark left by one.
Example: all those black smuts from the engine
Definition: [noun] a fungal disease of cereals in which parts of the ear change to black powder.
Example: a few bad crop years with smut and drought and frost
Definition: [noun] obscene or lascivious talk, writing, or pictures.
Example: porn, in his view, is far from being harmless smut