Norse tales unaffected by reversal (5)
I believe the answer is:
sagas
This might be a double definition.
'norse tales' is the first definition.
'sagas' can be an answer for 'tales' (I've seen this in another clue). I am not sure about the 'norse' bit.
'unaffected by reversal' is the second definition.
Can you help me to learn more?
(Other definitions for sagas that I've seen before include "Tales of heroes" , "Myths" , "Long involved stories" , "Heroic tales" .)