Difficult experience (6)
'difficult experience' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ordeal that I've seen before include "A tough time or hardship" , "very hard test" , "Difficult and painful experience" , "Suffering - trial" , "A difficult or harrowing time" .)
(Other definitions for hard time that I've seen before include "Tricky period" , "Unpleasant experience" .)