vacillating (adj.)

• adrift
• afloat
• alternating
• amorphous
• capricious
• changeable
• changeful
• coquettish
• desultory
• dizzy
• eccentric
• erratic
• faddish
• fickle
• fitful
• flickering
• flighty
• flirtatious
• fluctuating
• freakish
• giddy
• harmonic
• impetuous
• impulsive
• inconsistent
• inconstant
• indecisive
• infirm
• irregular
• irresolute
• irresponsible
• light
• mazy
• mercurial
• moody
• oscillating
• oscillatory
• pendulous
• periodic
• quicksilver
• rambling
• resonant
• restless
• roving
• scatterbrained
• shapeless
• shifting
• shifty
• skittish
• spasmodic
• spineless
• unaccountable
• uncertain
• uncontrolled
• undependable
• undisciplined
• unfixed
• unpredictable
• unreliable
• unrestrained
• unsettled
• unstable
• unsteady
• vagrant
• variable
• versatile
• vibratory
• volatile
• wandering
• wanton
• wavering
• wavy
• wayward
• whimsical
• wishy-washy
• wobbly