1. Scaly dry skin that has been exfoliated, such as dandruff.
2. A loose scaly crust coating a surface, especially of a plant.
3. Any of several fungal diseases of plants characterized by scaly lesions especially on underground parts, such as the tubers of potatoes.
[Middle English, probably of Scandinavian origin; see sker-1 in the Appendix of Indo-European roots.]
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