Alternative arrangement for trial (6)
I believe the answer is:
ordeal
'trial' is the definition.
(I know that ordeal is a type of trial)
'alternative arrangement' is the wordplay.
'alternative' becomes 'or'.
'arrangement' becomes 'deal' (arrangement between two people or groups).
'or'+'deal'='ORDEAL'
'for' acts as a link.
(Other definitions for ordeal that I've seen before include "A difficult or harrowing time" , "Difficult and testing experience" , "Ancient form of trial" , "Tribulation" , "A test of endurance or or difficult experience" .)