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.