Wait... So it's not just a made up fantasy name?
What does it translate to in English?

Viking zombie? Pretty much. Vikings had concepts of walking dead before most of the other westerners did, though Vikings were late to receive christianity and were always more connected with ancient beliefs. That still lingers today, in the Norwegian, Icelandic, Swedish, and to a lesser extent, Danish peoples.
EDIT: Beth probably got the idea of dragon shouts from the Draug, as old legends say some undead norseman could "pillage a boat with a roar of their tounge"