An Etymological Dictionary of the German Language/Annotated/Most
Most, masculine, ‘must, new wine,’ from Middle High German and Old High German most, masculine, ‘fermenting new wine, wine must;’ borrowed, like other words relating to vine-growing (see Wein, Winzer, Lauer, Presse, Torkel, and Kelch); the Latin origin is mustum, ‘must,’ whence also Anglo-Saxon, Middle English, and English must, the equivalent Dutch most, and in the Romance group, Italian mosto, French mout. Compare further Old Slovenian mŭstŭ.