From Proto-Germanic*swerdą(“literally ‘cutting, festering thing’”), of uncertain origin, but most likely ultimately from Proto-Indo-European*swer-(“‘fester,cut’ later ‘ wound’”).
Cognate with Old Frisian swerd (West Frisian swurd), Old Saxon swerd (Low German Sweerd), Old Dutch swert (Dutch zwaard), Old High German swert (German Schwert), Old Norse sverð (Danish sværd, Norwegian sverd, Swedish svärd)