1. (adjective) not firmly or solidly positioned

• unfirm

1. (adjective) subject to change or variation

• aflicker
• flickering
• arrhythmic
• jerking
• jerky
• convulsive
• spasmodic
• spastic
• faltering
• fluctuating
• palpitant
• palpitating
• quavering
• tremulous
• shaky
• shivering
• trembling
• shifting
• shifty
• shuddering
• tottering
• tottery
• uneven
• wobbling

2. (adjective) not firmly or solidly positioned

• unfixed

1. (adjective) subject to change or variation

• agitated
• irregular
• uneven
• unstable

1. (adjective) subject to change or variation

• unsteadiness

2. (adjective) not firmly or solidly positioned

• ricketiness
• unsteadiness

1. (adjective) subject to change or variation

• steady