Side roads backed up after abattoir evacuated (7)
I believe the answer is:
arsenal
'side' is the definition.
(English football club or side)
'roads backed up after abattoir evacuated' is the wordplay.
'roads' becomes 'lanes' (I've seen this in other clues).
'backed up' says the letters should be written in reverse.
'after' is a charade indicator (letters next to each other).
'evacuated' suggests removing the centre (internal letters are evacuated from the word).
'abattoir' with its middle taken out is 'ar'.
'lanes' in reverse letter order is 'senal'.
'senal' put after 'ar' is 'ARSENAL'.
(Other definitions for arsenal that I've seen before include "Weapons/ammo store" , "Cache of weapons or English soccer team" , "array of weapons" , "munitions factory" , "London FC" .)