tar spot
noun
Definition of tar spot
1a : a leaf-blotch disease of maple, willow, or oak caused by fungi of the genus Rhytisma that produces raised black stromatic cushions on the foliage b : one of the spots produced
2 : a disease of many grasses caused by a fungus (Phyllacora graminis) and resembling the tar spot of trees
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Origin and Etymology of tar spot
1tar
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