Enslave (9)
I believe the answer is:
subjugate
'enslave' is the definition.
(I know that enslave is a more specific form of the action subjugate)
This is the entire clue.
(Other definitions for subjugate that I've seen before include "Make subservient" , "Gain mastery over" , "Bring under domination" , "Manage to keep down" , "Crush" .)