...And so for the lazy but curious:
1.a small flake of soot or other dirt.
"all those black smuts from the engine"
synonyms: imperfection · fault · flaw · defect · deformity · discoloration · disfigurement
2.a fungal disease of grains in which parts of the ear change to black powder.
synonyms: mildew · fungus · must · moldiness · mustiness · blight · dry rot · wet rot
3.obscene or lascivious talk, writing, or pictures.
"porn, in this view, is far from being harmless smut"
synonyms: indecency · immorality · impropriety · salaciousness · smuttiness · lewdness ·
1.mark with flakes or soot or other dirt.
"the smutted sky"
2.infect (a plant) with smut.
Now I still don't know how Wheat Fungus applies to a house on fire - But...I'll leave this here for other folks to figure out.