(a.) Consisting in, or causing, vibration, or oscillation; vibrating; as, a vibratory motion; a vibratory power.

adrift afloat alternating amorphous broken capricious careening catchy changeable changeful choppy desultory deviable deviative disconnected discontinuous dizzy eccentric erratic fast and loose fickle fitful flickering flighty flitting fluctuant fluctuational freakish giddy guttering halting harmonic herky-jerky heteroclite immethodical impetuous impulsive inconsistent inconstant indecisive infirm intermittent intermitting irregular irresolute irresponsible jerky libratory lurching mazy mercurial moody nonuniform nutational oscillating oscillatory patchy pendular pendulating pendulous periodic rambling resonant restless rough roving scatterbrained scrappy shapeless shifting shifty shilly-shally shilly-shallying shuffling snatchy spasmatic spasmic spasmodic spastic spineless sporadic spotty staggering unaccountable uncertain uncontrolled undependable undisciplined unequal uneven unfixed unmethodical unmetrical unpredictable unregular unreliable unrestrained unrhythmical unsettled unstable unstable as water unstaid unsteadfast unsteady unsystematic vacillating vacillatory vagrant variable veering vibratile vibrating vibratory vicissitudinary vicissitudinous volatile wandering wanton wavering wavery wavy wayward whimsical wishy-washy wobbling wobbly