adjective
trembling
Synonyms: all aquiver, aquake, aquiver, ashake, faltering, fluctuant, infirm, insecure, jellylike, jerry-built, jittery, nervous, not set, precarious, quaking, quivery, rattletrap, rickety, rocky, rootless, shaking, tottering, tottery, tremorous, tremulous, tumbledown, unfirm, unsettled, unsound, unstable, unsteady, unsure, vacillating, wavering, weak, wobbly, yielding
Antonyms: firm, steady, unshaky, unwavering
adjective
doubtful
Synonyms: dubious, indecisive, not dependable, not reliable, precarious, problematic, questionable, suspect, uncertain, unclear, undependable, unreliable, unsettled, unsound, unsteady, unsupported, unsure
Antonyms: certain, firm, indubious, sure