back and forth
US /bæk ən fɔːrθ/
UK /bæk ən fɔːrθ/
1.
moving first in one direction and then in the opposite direction repeatedly
:
•
The pendulum swung back and forth.
•
They walked back and forth across the room.
2.
between two points, people, or places
:
•
The ball went back and forth between the players.
•
They exchanged emails back and forth for days.