Yes, Black Death isn't a direct translation of Brennivin, but the tradition, if I remember correctly is that it's informally called that because some Icelanders claimed it was what kept the entire island to avoid concracting the Black Death back in the middle ages.

And Brennivin is a dry schnapps or aquivit that is made from potatoes and flavored with caraway seeds. It's an aquired taste (don't ask me how I aquired it).