An Etymological Dictionary of the German Language/Annotated/Senf
Senf, masculine, ‘mustard,’ from the equivalent Middle High German sënf, sënef, masculine, Old High German sënaf, masculine; corresponding to Gothic sinap, Anglo-Saxon sënep, ‘mustard.’ The other dialects have, like Romance, the term Mostert. It cannot be determined through what medium Greek and Latin σίνᾶπι, sinâpi, ‘mustard,’ were introduced at so early a period that the Gothic and High German terms correspond; but since they are not genuine Aryan words, it is possible the South Teutons and Græco-Italians obtained them independently from the same source.