English head retired in German city (5)
I believe the answer is:
essen
'german city' is the definition.
(city in Germany)
'english head retired' is the wordplay.
'english' becomes 'e' (abbreviation).
'head' becomes 'ness' (ness is a headland).
'retired' says the letters should be written backwards.
'ness' reversed gives 'ssen'.
'e'+'ssen'='ESSEN'
'in' is the link.
(Other definitions for essen that I've seen before include "European city" , "Main industrial city of the Ruhr" , "German place name" , "Industrial city of northwest Germany" , "German industrial city on the Ruhr" .)