An Etymological Dictionary of the German Language/Annotated/Sünde
Sünde, feminine, ‘sin, offence,’ from the equivalent Middle High German sünde, Old High German suntu, suntea (base *sundî), feminine. Corresponding to Old Low German sundia, Dutch zonde; the equivalent Anglo-Saxon synn (English sin) is based on the primary form *sunjô for *sundjô; Old Icelandic synð also points to a Gothic *sunidi. Pre-Teutonic swntiâ-, swenetiâ-, belong to a pre-Teutonic root swen, sun, which, with a dental suffix, appear also in Greek ἄτη, ‘guilt, damage,’ Latin sons, ‘guilty,’ sonticus, ‘injurious.’