Back and forth

The back and forth movement of the tide causes erosion of the coastline.

Roll the ball to your child, who then rolls it back to you. After a few back-and-forths, roll the ball to a nearby corner of the room or other hiding place.

There's some back and forth between Simpson and his CIA counterparts and, in essence, the CIA says that you must ship all of the quantities requested.

It was months and months of back and forth, ah-ah, ah-ah You're still all over me like a wine-stained dress I can't wear anymore