Doctor needs fluid for German city (7)
I believe the answer is:
dresden
'for german city' is the definition.
(Dresden is a city in Germany)
'doctor needs fluid' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'fluid' is an anagram indicator.
'needs' is an anagram of 'esden'.
'dr'+'esden'='DRESDEN'
(Other definitions for dresden that I've seen before include "Fine china named after German city" , "Red Ned's in the German city" , "Germany city - reddens (anag)" , "Type of china" , "'German city, almost totally destroyed by British air raids in 1945 (7)'" .)