1. (n.) A play among children in which they are seated upon the opposite ends of a plank which is balanced in the middle, and move alternately up and down.

2. (n.) A plank or board adjusted for this play.

3. (n.) A vibratory or reciprocating motion.

4. (n.) Same as Crossruff.

5. (v. i.) To move with a reciprocating motion; to move backward and forward, or upward and downward.

6. (v. t.) To cause to move backward and forward in seesaw fashion.

7. (a.) Moving up and down, or to and fro; having a reciprocating motion.

Ferris wheel Lissajous figure alternate alternately alternation back and fill back and forth back-and-forth backward and forward backwards and forwards battledore and shuttlecock cant carousel chute-the-chutes chutes coaction come and go coming and going complementary distribution concurrence cooperation ebb and flow engagement flounder fluctuate flux and reflux flying horses go through phases hitch and hike in and out incline interaction interchange intercommunication intercourse interlacing intermeshing interplay intertwining interweaving interworking lean list lurch merry-go-round mesh meshing metronome mutatis mutandis off and on oscillate oscillator pass and repass pendulate pendulum pitch quid pro quo reciprocal reciprocally reciprocate reciprocation reciprocative rhythmic play ride and tie ring the changes rock rocker rocking chair rocking stone roll roller coaster round and round roundabout seesawing shift shuffle shuttle shuttlecock shuttlewise sine wave stagger swag sway swing teeter teeter-totter teeter-tottering teeterboard teetering teetery-bender tilt tilter tit for tat to and fro to-and-fro totter tottering turn up and down up-and-down ups and downs vacillate vary vibrator vice versa waver wax and wane whip whirligig wibble-wabble wigwag wobble yaw zigzag