Depart in some pain (5)
I believe the answer is:
agony
'pain' is the definition.
(agony is a kind of pain)
'depart in some' is the wordplay.
'depart' becomes 'go' ('go' can be a synonym of 'depart').
'in' is an insertion indicator.
'some' becomes 'any' ('any' can be similar in meaning to 'some').
'go' going into 'any' is 'AGONY'.
(Other definitions for agony that I've seen before include "Pain, torment" , "Really severe pain" , "This aunt answers readers' questions" , "sort of aunt" , "Severe pain, mental or physical" .)