Relating to districts outside the city centre (8)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
suburban
(Other definitions for suburban that I've seen before include "Relating to the outskirts of a town" , "Like outer city areas" , "Relating to outer city areas" , "Relating to outskirts of city" , "Residential district on a city's outskirts" .)