An Etymological Dictionary of the German Language/Nobistrug
Nobistrug, m., ‘underwold, hell,’ borrowed, like Krug, ‘tavern,’ the second part of the compound, in early ModHG. from LG. The first component is MidHG. abis, abyss, m., ‘abyss,’ whence with n prefixed (comp. Ital. nabisso, from the usual combination in abysso), the LG. form Nobisfrung, hence lit. ‘tavern in hell’