v.1. To enter some place forcibly: Someone broke into our house while we were gone and stole our TV.
2. To access a computer or computer network illegally or maliciously: We believe spies are breaking into the government's computer files.
3. To interrupt something: I'm sorry that I have to break into your nap, but it's important that I speak to you now.
4. To begin to do something suddenly: The horse broke into a wild gallop. The upset child broke into a flood of tears.
5. To enter some established profession or field of activity: The young writer broke into journalism right after college.