If you are unsteady, you have difficulty doing something, for example walking, because you cannot completely control your legs or your body. The boy was very unsteady and had staggered around when he got up He poured coffee into the mugs, and with an unsteady hand, held one of them out to David. + unsteadily un·steadi·ly She pulled herself unsteadily from the bed to the dresser
If you describe something as unsteady, you mean that it is not regular or stable, but unreliable or unpredictable. His voice was unsteady and only just audible