God who gave up an eye to gain wisdom (4)
I believe the answer is:
odin
'god who gave up an eye to gain wisdom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for odin that I've seen before include "Old Scandinavian" , "Scandinavian war god" , "Legendary Scandinavian" , "God - I nod (anag)" , "Mythological Norse deity" .)