or Midgardsormen (i.e. earth's monster). The great serpent, brother of Hela and Fenrir (q.v.), and son of Loki, the spirit of evil. It used to lie at the root of the celestial ash till All-Fader cast it into the ocean; it then grew so large that in time it encompassed the whole world, and was for ever biting its own tail.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894