Going faster, a county council held centre back of Bourke with assessment (12)
I believe the answer is:
accelerating
'going faster a county council' is the definition.
I can't tell whether this defines the answer.
'held centre back of bourke with assessment' is the wordplay.
'held centre' becomes 'accel' (I can't explain this - if you can you should believe this answer much more).
'back of' suggests the final letters.
'with' says to put letters next to each other.
'assessment' becomes 'rating' (rating is a kind of assessment).
The last letter of 'bourke' is 'e'.
'accel'+'e'+'rating'='ACCELERATING'
Can you help me to learn more?
(Other definitions for accelerating that I've seen before include "Gaining speed" , "Increasing speed" .)