scurf

Concise Oxford English Dictionary © 2008 Oxford University Press:
scurf/skəːf/

▶noun flakes on the surface of the skin that form as fresh skin develops below, occurring especially as dandruff.

■ a similar flaky deposit on a plant resulting from a fungal infection.

– derivatives
scurfy adjective.

– origin OE sceorf, from the base of sceorfan ‘gnaw’, sceorfian ‘cut to shreds’.