noun
: any pathological state in a plant characterized by brown discoloration and disintegration of the phloem: as
a. : a phase of potato leaf roll in which such changes occur
b. : a virus disease of tea
c. : a fatal virus disease of the American elm widespread in the United States characterized by yellowish often black-flecked discoloration and degeneration of the phloem and resulting in death of the root system through lack of food followed by wilting, yellowing, and loss of leaves