From Middle High German schimel, schimmel, from Old High German skimbal (“mould”). The expected Middle High German form is seemingly unattested *schimbel, but all three forms (schimel, schimmel, *schimbel) would have yielded modern German Schimmel. Cognate with Dutch schimmel (“mould”).
Schimmel m (genitive Schimmels, no plural)
- (mildew): Mehltau
Derived from etymology 1 due to the similar colour. At first an attributive construction, seemingly of northern origin, in Middle Low German dat scymelinghe perd (1373) and Middle High German ein schemeliges perd (1374, West Central German). Dutch schimmel (“grey horse”) is borrowed from German.
Schimmel m (genitive Schimmels, plural Schimmel)
- Schimmel in Duden online