The final goal (3)
I believe the answer is:
end
This clue is a double definition.
'the final' is the first definition.
(thesaurus)
'goal' is the second definition.
(both can mean a purpose)
(Other definitions for end that I've seen before include "Finish, wind up" , "scrap" , "border?" , "Bring to a close" , "target" .)