City takes back county (5)
I believe the answer is:
yorks
'county' is the definition.
(short for Yorkshire)
'city takes back' is the wordplay.
'city' becomes 'york' (York is a city).
'takes back' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'york'+'s'='YORKS'
Can you help me to learn more?
(Other definitions for yorks that I've seen before include "Whitby's county (abbrev.)" , "Ilkley's county" , "County (abbreviation)" , "Gas oven setting" , "Where you may get pudding" .)