What it means

1. verb make submissive, obedient, or useful
   “The horse was tough to break”
2. verb break so as to fall inward
   “He broke in the door”
3. verb start in a certain activity, enterprise, or role
4. verb intrude on uninvited
   “The nosy couple broke in on our conversation”
5. verb enter someone's (virtual or real) property in an unauthorized manner, usually with the intent to steal or commit a violent act
   “Someone broke in while I was on vacation”
6. verb break into a conversation
   “her husband always chimes in, even when he is not involved in the conversation”