It makes sense in the Ruhr (5)
I believe the answer is:
essen
'in the ruhr' is the definition.
(city in the Ruhr region of Germany)
'it makes sense' is the wordplay.
'it makes' indicates anagramming the letters.
'sense' is an anagram of 'ESSEN'.
(Other definitions for essen that I've seen before include "Industrial centre of the Ruhr" , "European city" , "Industrial city of northwest Germany" , "German industrial city on the Ruhr" , "German place name" .)