Definition of "break into"

break into

verb
third-person singular simple present breaks into, present participle breaking into, simple past broke into, past participle broken into
1. (transitive, idiomatic) To enter illegally or by force, especially in order to commit a crime.
2. (transitive, idiomatic) To open or begin to use.
3. (transitive, idiomatic) To successfully enter a profession or business.
4. (transitive) To begin suddenly.
  Quotations
  Then, as usual, the sheep broke into "Four legs good, two legs bad!" and the momentary awkwardness was smoothed over.
  1945 August 17, George Orwell [pseudonym; Eric Arthur Blair], chapter 6, in Animal Farm […], London: Secker & Warburg
  That struck me as hilarious, and I broke into hysterical giggles. And once I began, I couldn’t stop. I laughed until I was gasping for breath, tears streaming down my face.
  2010, Julie Kagawa, The Iron King, Don Mills: Harlequin Teen, page 237