| a disease of chestnuts, esp. the American chestnut, characterized by bark lesions that girdle and eventually kill the tree, caused by a fungus, Endothia parasitica. |
| chestnut blight n. A disease of chestnut trees caused by a fungus (Cryphonectria parasitica) that is especially destructive to the American chestnut, characterized by cankers that eventually kill the branches and trunk. |