indubitable

not capable of being challenged or proved wrong the indubitable fact that there are no more woolly mammoths or saber-toothed tigers around Synonyms accomplished, certain, inarguable, incontestable, incontrovertible, indisputable, irrefutable, irrefragable, positive, sure, unanswerable, unarguable, unchallengeable, undeniable, unquestionableRelated Words unambiguous, unequivocal; absolute, clear, conclusive, decisive, definite, hands-down; uncontested, uncontradicted, undisputed, unquestionedNear Antonyms controversial, debated, disputed; doubtful, dubious, iffy, inconclusive, indecisive, uncertain; ambiguous, equivocal; academic (also academical), hypothetical, speculative, theoretical (also theoretic)Antonyms answerable, arguable, contradictable, controvertible, debatable, disputable, doubtable, moot, negotiable, problematic (also problematical), questionable, refutable