Scurf
SCURF, noun [L. scorbutus.]
1. A dry military scab or crust formed on the skin of an animal.
2. The soil or foul remains of any thing adherent; as the scurf of crimes. [Not common nor elegant.] Dryden.
3. Any thing adhering to the surface.
There stood a hill, whose grisly top Shone with a glossy scurf. Milton.