IPA: //ʌnˈstɛdɪli//
KK: /ʌnˈstɛdɪli/
In a way that is not steady; shaking or wobbling while moving or doing something.
She walked unsteadily after getting off the roller coaster.
Unsteadily → It is formed from "un-" (meaning not) and "steady" (from Old English *stædige*, meaning firm or stable) and the suffix "-ly" (meaning in a manner of). The word "unsteadily" means in a manner that is not firm or stable.
Think of 'not' ('un-') being added to 'steady' to remember that 'unsteadily' means not firm or stable.