With apt reason I arranged for divorce (10)
I believe the answer is:
separation
'divorce' is the definition.
(thesaurus)
'with apt reason i arranged' is the wordplay.
'with' is a charade indicator (letters next to each other).
'arranged' is an anagram indicator.
'apt'+'reason'='aptreason'
'aptreason' next to 'i' is 'aptreasoni'.
'aptreasoni' is an anagram of 'SEPARATION'.
'for' acts as a link.
(Other definitions for separation that I've seen before include "Disunion" , "divorce" , "Detachment" , "Split" , "One is apart (anag)" .)