break-in

Trespassing for an unlawful purpose; illegal entrance into premises with criminal intent.

Enter someone's (virtual or real) property in an unauthorized manner, usually with the intent to steal or commit a violent act.

Break into a conversation.

Make submissive, obedient, or useful.

Break so as to fall inward.

Intrude on uninvited.

Start in a certain activity, enterprise, or role.