Ferris wheel, Lissajous figure, alternate, alternately, alternation, back-and-forth, back and fill, 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-totter, teeter-tottering, teeter, 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