smut

Etymology

From Middle English smutten (“to defile, debase”), related to German Schmutz (“filth, dirt, smut”) and schmutzen (“to make dirty, stain”). Doublet of schmutz. Compare also Old English smitta (“smear; blot; mark; stain; pollution”), Old English besmītan (“to besmut; defile; dirty; pollute; contaminate”).

noun

1. (uncountable) Soot.
2. (countable) A flake of ash or soot.
   She reached it soon after half-past two. She found its gloomy nineteenth-century façade, black with the smuts of ninety years, a little daunting, and mounted its broad steps in some trepidation. But she rang the bell hard and knocked firmly. 1915, Edgar Jepson, “The Reluctant Duke”, in Happy Pollyooly: The Rich Little Poor Girl, Indianapolis, Ind.: The Bobbs-Merrill Company, →OCLC, page 135
   “You can rely on me!” Varya said, still more earnestly and enthusiastically, still leaning heavily on the counter, noticing briefly and forgetting at once that her bare elbow had crushed a stray smut from the Primus mender's booth. 1989, Aleksandr Solzhenitsyn, translated by Harry Willetts, August 1914, Farrar, Straus and Giroux, page 56
   “Do I have a smut on my nose, Mr. Donovan? You've been staring at me for a full minute. It's most disconcerting, you know.” 2012, Kasey Michaels, A Masquerade in the Moonlight
3. (uncountable) Sexually vulgar material; something that is sexual in a dirty way; pornographic material.
4. (uncountable) Obscene language; ribaldry; obscenity.
5. Any of a range of fungi, mostly Ustilaginomycetes, that cause plant disease in grasses, including cereal crops; the disease so caused.
6. (mining) Bad, soft coal containing earthy matter, found in the immediate locality of faults.

verb

1. (transitive, intransitive) To stain (or be stained) with soot or other dirt.
2. (transitive) To taint (grain, etc.) with the smut fungus.
3. (intransitive) To become tainted by the smut fungus.
   It smutted to a far greater degree than the year before, say three fourths, or more. I obtained but little more than the seed sown, and that was handsome wheat. This failure I imputed to the same supposed cause which operated the last year. 1836, New England Farmer, volume 14, page 313
4. (transitive) To clear of the smut fungus.
   to smut grain for the mill