Blacken in Nippon (5)
I believe the answer is:
japan
This could be a double definition.
'blacken' is the first definition.
Although both the answer and definition are verbs in their base form, I cannot see how one could define the other.
'nippon' is the second definition.
(synonyms)
'in' is the link.
Can you help me to learn more?
(Other definitions for japan that I've seen before include "It's a string of more than 3,000 islands" , "Glossy black lacquer" , "Country and decorated black lacquerware" , "Country in Far East" , "Land of the Rising Sun" .)