fall in with

fall in with  {v.},  {informal}
1. To meet by accident.
Mary fell in with some of her friends downtown.
2. To agree to help with; support.
I fell in with Jack's plan to play a trick on his father.
3. To become associated with a group detrimental to the newcomer.
John fell in with a wild bunch; small wonder he flunked all of his courses.
Compare: PLAY ALONG.
Categories: informal verb