Humped beast city attorney found in arid surroundings (9)
I believe the answer is:
dromedary
'humped beast' is the definition.
(I know this)
'city attorney found in arid surroundings' is the wordplay.
'city' becomes 'rome' (Rome is an example).
'attorney' becomes 'D.A.' (abbreviation for District Attorney).
'found in' means one lot of letters goes inside another.
'arid' becomes 'dry' (similar in meaning).
'surroundings' indicates putting letters inside.
'da' placed into 'dry' is 'ddary'.
'rome' put inside 'ddary' is 'DROMEDARY'.
(Other definitions for dromedary that I've seen before include "Arab racer" , "Creature" , "Animal" , "Desert traveller" , "desert transport" .)