Colosseum setting (4)
I believe the answer is:
rome
'colosseum setting' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rome that I've seen before include "Italian capital (where one Ac died)" , "Italian city" , "European capital" , "When here, do as the citizens do" , "The Eternal City" .)