Tví-bytna

Meaning of Old Norse word "tví-bytna"

As defined by the Cleasby & Vigfusson Old Norse to English dictionary:

tví-bytna

u, f. a bottomless lake or pit, in popular belief, or thought to be in hidden connection with the sea.

Possible runic inscription in Younger Futhark:ᛏᚢᛁ-ᛒᚢᛏᚾᛅ
Younger Futhark runes were used from 8th to 12th centuries in Scandinavia and their overseas settlements