>>17863777From a word for “sullen face, mean-spirited person”, which still survives in Flemish moef. This is usually considered a borrowing from German Muff (now dialectal in this sense), though it could also be a native formation; compare Middle Dutch moffelen (“to grumble”). Ultimately onomatopoeic. The ethnic sense first occurred in the form Hans Mof (16th century).
mof m (plural moffen, diminutive mofje n, feminine moffin)
(derogatory) German, Kraut
Synonyms: Duitser, Moffrikaan
(obsolete) an eastern immigrant to Holland (especially from Germany, but also Gelderland, Overijssel etc.)