An Etymological Dictionary of the German Language/Annotated/Mostert

by Friedrich Kluge

Mostert, Mostrich, masculine (the second word is a corruption of the first), ‘mustard,’ Middle High German mostert, musthart, masculine, ‘mustard mixed with must’; corresponding to the Romance terms, Italian mostarda, French moutarde, whence Middle English and English mustard, Dutch mosterd. A derivative of Latin mustum, ‘must,’ mustard being mixed with must. Compare Senf.