Discipline or subdue (7)
I believe the answer is:
chasten
This clue is a double definition.
'discipline' is the first definition.
(I've seen this before)
'subdue' is the second definition.
(I know that subdue can be written as chasten)
(Other definitions for chasten that I've seen before include "Moderate" , "Suppress" , "Punish, purify" , "Censure severely" , "Castigate or punish" .)