Outcome in Ypres, ultimately (6)
I believe the answer is:
result
'outcome' is the definition.
('result' can be a synonym of 'outcome')
'in ypres ultimately' is the wordplay.
'in' indicates the answer is hidden within the clue.
'RESULT' can be found hidden inside 'ypres ultimately'.
(Other definitions for result that I've seen before include "Verdict" , "Outcome of an undertaking" , "Effect - outcome" , "Ulster (anag) - outcome" , "End - issue" .)