An Etymological Dictionary of the German Language/Senf
Senf, m., ‘mustard,’ from the equiv. MidHG. sënf, sënef, m., OHG. sënaf, m.; corresponding to Goth. sinap, AS. sënep, ‘mustard.’ The other dials. have, like Rom., the term Mostert. It cannot be determined through what medium Gr. and Lat. σίνᾶπι, sinâpi, ‘mustard,’ were introduced at so early a period that the Goth. and HG. terms correspond; but since they are not genuine Aryan words, it is possible the South Teutons and Græco-Itals. obtained them independently from the same source.