Missýnast

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

missýnast

(see sýna), v. refl., e-m missýnist, one sees wrong, is mistaken (allmjök missýnist slíkum manni sem Broddier).

Possible runic inscription in Younger Futhark:ᛘᛁᛋᛋᚢᚾᛅᛋᛏ