to break in
to break in: gradually to prepare something for use that is new and stiff;
to interrupt (for the second definition, also: to cut in)
to interrupt (for the second definition, also: to cut in)
Examples of TO BREAK IN
- It is best to break a new car in by driving it slowly for the first few hundred miles.
- While Carrie and I were talking, Bill broke in to tell me about a telephone call.