Is to prosecute as the outcome (5)
I believe the answer is:
issue
'the outcome' is the definition.
(thesaurus)
'is to prosecute' is the wordplay.
'to prosecute' becomes 'sue' (I've seen this before).
'is'+'sue'='ISSUE'
'as' is the link.
(Other definitions for issue that I've seen before include "Subject to discuss" , "Children, edition" , "Outcome - discharge" , "Number (of periodical)" , "Matter for discussion" .)