The aim is to reach a conclusion (3)
I believe the answer is:
end
This clue is a triple definition!
'the aim' is the first definition.
(I've seen this before)
'is to' is the second definition.
(thesaurus)
'reach a conclusion' is the third definition.
(Other definitions for end that I've seen before include "Purpose of finish" , "Aim - point - finish" , "Terminate in den" , "SECOND PART OF 10" , "Fine" .)