Rode off behind a city's airfield (9)
I believe the answer is:
aerodrome
'airfield' is the definition.
(aerodrome is a kind of airfield)
'rode off behind a city's' is the wordplay.
'off' indicates an anagram.
'behind' says to put letters next to each other.
'city' becomes 'rome' (Rome is an example).
'rode' is an anagram of 'erod'.
'erod' after 'a' is 'aerod'.
'aerod'+'rome'='AERODROME'
(Other definitions for aerodrome that I've seen before include "Take windy Rome road East to the airfield" , "home of metal birds?" , "Where one might land" , "Small airport" , "place that may be alighted on" .)