Slowly destroy what a Norseman did, said East Ender (5)
I believe the answer is:
erode
'slowly destroy' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for erode that I've seen before include "fragment" , "Abrade" , "Eat away" , "'Deteriorate, wear away (5)'" , "Become ground down or deteriorate" .)