Æðrast

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

æðrast

(að), v. refl. to falter from fear, lose heart (eigi skyldim vér ~ at leggja til bardaga).

Possible runic inscription in Younger Futhark:ᛅᚦᚱᛅᛋᛏ

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