Slid

According to the Prose Edda Slid or Slith was one of the Elivagar's streams, floating out the well Hvergelmir.

"From the east there pours | through poisoned vales
With swords and daggers | the river Slith."
(Poetic Edda: Völuspá)

Old Norse: Slíðr
Meaning: "Terrible"