(More fully "grey leaf spot", "grey leaf blight") any of numerous plant diseases in which the leaves develop greyish lesions, especially due to fungal infection or nutrient deficiency.
Origin
Early 20th century.
Definition of grey leaf in US English:
grey leaf
(USgray leaf)
noun
(More fully "grey leaf spot", "grey leaf blight") any of numerous plant diseases in which the leaves develop greyish lesions, especially due to fungal infection or nutrient deficiency.