Breaking-in

Breaking-in (or just breaking) a submissive or slave is the practice of destroying resistance and thereby ensuring obedience. It may be likened to breaking in a horse, or a pair of shoes.

It is a controversial practice - or at least phrase - which is defended by those who say it is nothing more nor less than might be used in The Taming of the Shrew and attacked by those who consider the methods used to be cruel and inhumane, whether used on an animal or consensual human.