An Etymological Dictionary of the German Language/Annotated/Schmaus
Schmaus, masculine, ‘feast, banquet’; its history and origin are obscure. Yet Dutch smullen, ‘to eat or drink immoderately, carouse,’ smuisteren, ‘to feast, Dutch and Low German smudderen, smodderen, ‘to feast,’ are probably cognate. The word is unknown to the Old Teutonic period.