Cross and unwilling to follow the rules initially (8)
I believe the answer is:
'cross' is the definition.
('traverse' can be a synonym of 'cross')
'unwilling to follow the rules initially' is the wordplay.
'unwilling' becomes 'averse' (I've seen this before).
'to follow' means one lot of letters go next to another.
'initially' says to take the initial letters.
The first letters of 'the rules' is 'tr'.
'averse' put after 'tr' is 'TRAVERSE'.
'and' acts as a link.
(Other definitions for traverse that I've seen before include "Travel across or pass over" , "cover" , "Extend or bridge across" , "Go across" , "In mountaineering, a steep slope to be crossed from side to side" .)