Bœttr

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

bœttr

pp. (cf. bœta) atoned for; er mér ekki sonr minn at bœttari, þótt Bolli sé drepinn, my son’s death is none the more atoned for though B. is slain; ok er eigi at ~a, þótt, things are no better though.

Possible runic inscription in Younger Futhark:ᛒᚢᛏᛏᚱ