Goal to finish (3)
I believe the answer is:
end
I believe this clue is a double definition.
'goal' is the first definition.
(both can mean a purpose)
'finish' is the second definition.
(I know that finish can be written as end)
'to' is the link.
(Other definitions for end that I've seen before include "Aim or goal" , "Bring to a conclusion" , "Game at bowls" , "Extreme" , "'Conclusion, finale (3)'" .)