Óttast

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

óttast

(að), v. refl. to fear (~ e-n); ~ at sér, um sik, to be anxious (concerned) about oneself.

Possible runic inscription in Younger Futhark:ᚢᛏᛏᛅᛋᛏ