Stop time when hurt (6)
I believe the answer is:
damage
'hurt' is the definition.
(I know that hurt is a more specific form of the action damage)
'stop time' is the wordplay.
'stop' becomes 'dam' (I've seen this in other clues).
'time' becomes 'age' (an age is a period of time).
'dam'+'age'='DAMAGE'
'when' acts as a link.
(Other definitions for damage that I've seen before include "destruction" , "'Deface, impair (6)'" , "Deface, harm" , "Harm; reparation" , "Harm, impair" .)