break in

verb breaks in · breaking in · broke in · broken in

1. intransitive To enter a place by force or illicit means. Someone broke in and stole his radio.
2. transitive To smash (something) by forcing it inward. Break in the door. We are held up!
3. ambitransitive, ergative, idiomatic To reach a state of functioning more smoothly through use or wear; to cause (something, or someone, new) to undergo this change. These shoes will be more comfortable after they have broken in.

   Similar: run in, wear in

4. idiomatic, transitive Starting something brand new or at a new level. He broke in with the New York Yankees.
5. transitive, of a horse To tame; make obedient; to train to follow orders of the owner. Captain had been broken in and trained for an army horse; his first owner was an officer of cavalry going out to the Crimean War. He said he quite enjoyed the training with all the other horses, trotting together, turning together, to the right hand or to the left, halting at the word of command, or
6. colloquial, transitive To take the virginity of a girl, to deflower. While brothel patrons placed their bets / On who would be the first to break her in
7. intransitive To interrupt one's conversation; speak before another person has finished speaking.
8. slang, transitive To initiate a new person into prostitution or prison sex acts.