An Etymological Dictionary of the German Language/Annotated/Seneschall
Seneschall, masculine, ‘seneschal, high steward,’ from the equivalent Middle High German seneschalt, sineschalt, masculine, which is derived from Romance; compare the cognates French sénéchal, Italian siniscalco (Middle Latin siniscalcus), ‘high steward.’ The Romance words are based on an Old Teutonic word (Gothic *sinaskalks, ‘head servant’); compare Gothic sinista, ‘eldest,’ which is primitively allied to Old Irish sen, Latin senex, senior, Lithuanian sénas, Sanscrit sánas, ‘old.’ With regard to the second part of the compound compare Schalk (and Marschall). The invariable t at the end of the Middle High German word is remarkable.