get (one) to flip

1. sports To convince an athlete to transfer from one team to another. Primarily heard in US. Recruiters at Notre Dame have been trying to get Marcus Jackson to flip all season, but he seems set on remaining with OSU. If he's been at that school for three years already, what kind of offer will get him to flip now? Well, of course, we would have preferred to sign her out of high school, but we couldn't, so we just have to try to get her to flip now.

2. To convince one to betray or inform against (someone). Typically followed by "on." Primarily heard in US. We're trying to get the gang member to flip, but so far he won't say a word. If we can just get one of these guys to flip, we can find who really orchestrated the cover-up at City Hall. Good luck getting Al to flip. He knows what mob thugs do to snitches.