to teach a horse to tolerate being handled/ridden; very earliest schooling

enter someone's property in an unauthorized manner, usually with the intent to steal or commit a violent act; "Someone broke in while I was on vacation"; "They broke into my car and stole my radio!"

break into a conversation; "her husband always chimes in, even when he is not involved in the conversation"

The act of breaking through a kill's skin, usually starting at the soft underbelly.

start in a certain activity, enterprise, or role