sure

Synonyms: abiding assured changeless clear confident constant convinced convincing decided doubtless enduring firm fixed for a fact free from doubt genuine incontestable incontrovertible indisputable indubitable never-failing persuaded positive real satisfied set steadfast steady telling unchangeable unchanging uncompromising undeniable unequivocal unfailing unfaltering unqualified unquestionable unquestioning unshakable unshaken unvarying unwavering valid

Antonyms: doubtful dubious indefinite uncertain unsure variable wavering

Synonyms: fast firm fixed safe secure solid staunch steady strong

Antonyms: swerving unsteady unsure wavering wobbly

Synonyms: assured bound certain guaranteed indisputable ineluctable inerrant inescapable infallible irrevocable surefire unavoidable unerring unfailing

Antonyms: doubted doubtful dubious unsure

Synonyms: arrogant assured certain composed confident decided decisive positive self-assured self-possessed

Antonyms: humbled uncertain unconfident unself-confident unsure