0 in one direction and then in the opposite direction, a number of times: --
She was gazing out the window, rocking rhythmically to and fro.
Only on the forestage can people hurry to and fro, as in a city street.
The rising plumes swing to and fro and the upper flux concentration moves between them.
Another hydraulic actuator enabled the hip to move to and fro.
The "to and fro" motion of electrons near the grid contributes, together with the electromagnetic energy flow, to the feedback of the microwave generator.
The audience is drawn into the action and there is a relaxed flow of communication to and fro.
A computer stores and processes information; linked with other computers on a computer network, it can also pass information to and fro.
The whole process was repeated a few times before beginning to rock to and fro in this position.
The inexorable persistence of the opening motive conjures up a grief-stricken widow, rocking to and fro in her overwhelming sorrow.