1. unsteady Uncertain is applied to things that human knowledge can not certainly determine or that human power can not certainly control; precarious originally meant dependent on the will of another, and no Synonyms: precarious, doubtful, hazardous, risky, unsettled, dubious, insecure, unassured, unstable, equivocal, perilous, uncertain, unsteady Antonyms: actual, immutable, real, steady, undeniable, assured, incontestable, settled, strong, undoubted, certain, infallible, stable, sure, unquestionable, firm