Synonyms and related words :
alternate, beating, circling, cyclic, epochal, even, every other, fluctuant, fluctuating, fluctuational, harmonic, intermittent, isochronal, libratory, measured, metronomic, nutational, oscillating, pendular, pendulating, pendulous, periodic, periodical, pulsing, reciprocal, recurrent, recurring, resonant, rhythmic, rotary, seasonal, serial, shilly-shally, shilly-shallying, steady, undulant, undulatory, vacillating, vacillatory, vibratile, vibrating, vibratory, wavelike, wavering, wheeling, wobbly