Subjugate by force (7)
I believe the answer is:
oppress
'subjugate by force' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for oppress that I've seen before include "Weigh down with cares, be cruel" , "Be brutal to" , "Trample down" , "Bear down hard on" , "Treat cruelly" .)