River Don (4)
I believe the answer is:
wear
I believe this is a double definition.
'river' is the first definition.
(river in the north east of England)
'don' is the second definition.
(synonyms)
(Other definitions for wear that I've seen before include "Become tiresome" , "___ and tear" , "Northern flower" , "Clothes; chafe" , "assume" .)