noun
1. : a destructive disease of plum and cherry trees characterized by black excrescences on the branches and caused by a fungus ( Dibotryon morbosa )
2. : a destructive disease of the gooseberry characterized by black excrescences on the branches and caused by a fungus ( Dibotryon ribesia )
3. : a disease of the filbert and hazel characterized by black warty excrescences on the bark and caused by a fungus ( Cryptosporella anomala )
4. : a cane infection of the grape caused by the crown-gall bacterium