Side roads backed up on Axminster's outskirts (7)
I believe the answer is:
arsenal
'side' is the definition.
(English football club or side)
'roads backed up on axminster's outskirts' is the wordplay.
'roads' becomes 'lanes' (I've seen this in other clues).
'backed up' says the letters should be written backwards.
'on' is a charade indicator (letters next to each other).
'outskirts' means to remove the middle letters (I've seen 'outskirts of' mean this).
'axminster' with its middle removed is 'ar'.
'lanes' backwards is 'senal'.
'senal' after 'ar' is 'ARSENAL'.
(Other definitions for arsenal that I've seen before include "Premier League side founded by munitions workers in 1886" , "Gunners of North London" , "London FC" , "Munitions store and English football team" , "London premiership football team" .)