Unsteady

• Unstable
• Not stable

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1827, from Greek astatos "unstable, not steadfast," from a- , privative prefix (see a- (3)), + statos "placed, standing," from PIE root *sta- (see stet ).

WordNet Word definitions in WordNet
adj. not static or stable

Wiktionary Word definitions in Wiktionary
a. 1 Not static or stable; unsteady, unstable 2 (context medicine English) Of or pertaining to astasia

Wikipedia Word definitions in Wikipedia
The Astatic was a French cyclecar manufactured from 1920 to 1922 by Automobiles Astatic, Saint-Ouen , Seine, France. Built at Saint-Ouen, the car was an attempt to market a vehicle with independent suspension all round. This was done by coupling each wheel ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Astatic \A*stat"ic\, a. [Pref. a- not + static.] (Magnetism) Having little or no tendency to take a fixed or definite position or direction: thus, a suspended magnetic needle, when rendered astatic, loses its polarity, or tendency to point in a given direction. ...