Snooker shot (2-3)
I believe the answer is:
in-off
'snooker shot' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for in-off that I've seen before include "Losing hazard at billiards" , "Billiards/snooker shot" , "Pocketing of a snooker ball via a deflection" , "Glancing billiards pot" , "Error in game" .)