The end is not in reach (7)
I believe the answer is:
outcome
'the end' is the definition.
(thesaurus)
'not in reach' is the wordplay.
'not in' becomes 'out' ('out' is the opposite to 'in').
'reach' becomes 'come' (I've seen this in other clues**).
'out'+'come'='OUTCOME'
'is' is the link.
(Other definitions for outcome that I've seen before include "answer" , "'Result, upshot (7)'" , "Eventuality" , "Result or consequence" , "Cute moo (anag.)" .)