Hopeless case in passing, one released (5)
I believe the answer is:
goner
'hopeless case' is the definition.
(I've seen this before)
'in passing one released' is the wordplay.
'in' indicates the answer is hidden within the clue.
'GONER' can be found hidden inside 'passing one released'.
(Other definitions for goner that I've seen before include "Person beyond saving" , "One beyond help" , "Nasty princess" , "one with no life left" , "Person beyond help" .)