foul matter, like soot or coal dust; also, a spot or soil made by such matter.-bad, soft coal, containing much earthy matter, found in the immediate locality of faults.-an affection of cereal grains producing a swelling which is at length resolved into a powdery sooty mass. it is caused by parasitic fungi of the genus ustilago. ustilago segetum, or u. carbo, is the commonest kind; that of indian corn is ustilago maydis.-obscene language; ribaldry; obscenity.-to stain or mark with smut; to blacken with coal, soot, or other dirty substance.-to taint with mildew, as grain.-to blacken; to sully or taint; to tarnish.-to clear of smut; as, to smut grain for the mill.-to gather smut; to be converted into smut; to become smutted.-to give off smut; to crock.