Final goal? (3)
I believe this clue is a double definition.
'final' is the first definition.
(synonyms)
'goal?' is the second definition.
(both can mean a purpose)
(Other definitions for end that I've seen before include "Finish, close" , "Aim - point - finish" , "Terminus" , "Fine" , "Conclusion, finish" .)
(Other definitions for decider that I've seen before include "Crucial final game" , "crucial match" , "Final tie-breaker" , "Important match" , "Clinching game" .)