Allfastorðr

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

allfastorðr

a. very true to one’s word.

Possible runic inscription in Younger Futhark:ᛅᛚᛚᚠᛅᛋᛏᚢᚱᚦᚱ

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