The former capital of West Germany (4)
I believe the answer is:
bonn
'the former capital of west germany' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bonn that I've seen before include "First capital of the German Federal Republic" , "Former West German capital" , "W German capital 1949-90" , "Beethoven's birthplace, old capital" , "German city" .)