Access to go round Bill's track
I believe the answer is:
racecourse
'track' is the definition.
('racecourse' can be a synonym of 'track')
'access to go round bill's' is the wordplay.
'access' becomes 'recourse' (I've seen this before**).
'to go round' is an insertion indicator.
'bill' becomes 'ac'.
'recourse' going around 'ac' is 'RACECOURSE'.
(Other definitions for racecourse that I've seen before include "Aintree, for example" , "E.g. Ascot" , "Eg, Aintree" , "Running track for horses" , "Venue for meeting" .)