Úsœkiligr

As defined by A Concise Dictionary of Old Icelandic (Geir Zoëga):

úsœkiligr

a. impregnable.

Possible runic inscription in Younger Futhark:ᚢᛋᚢᚴᛁᛚᛁᚴᚱ

Also available in related dictionaries:

This headword also appears in dictionaries of other languages closely related to Old Icelandic.

• Old Norwegian - Johan Fritzner's Dictionary