Self-imposed punishment (7)
I believe the answer is:
penance
'self-imposed punishment' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for penance that I've seen before include "act of self-punishment" , "Punishment inflicted on oneself" , "Reparation" , "Voluntary self-abasement" , "Hardship" .)