20%RatingSave Gender Masculine Usage Ancient Germanic [1] Meaning & History Derived from the Germanic elements sigu "victory" and dag "day". Family Tree·DetailsRelated Names Other Languages & CulturesSiet, Sietse(Frisian) Sources & References Förstemann, Ernst. Altdeutsches Namenbuch. Bonn, 1900, page 1323. Entry updated February 4, 2020 ·