unchallengeable

not capable of being challenged or proved wrong the contention that there are certain unchallengeable rules governing proper grammar Synonyms of unchallengeable accomplished, certain, inarguable, incontestable, incontrovertible, indisputable, indubitable, irrefragable, positive, sure, unanswerable, unarguable, irrefutable, undeniable, unquestionableWords Related to unchallengeable unambiguous, unequivocal; absolute, clear, conclusive, decisive, definite, hands-down; uncontested, uncontradicted, undisputed, unquestionedNear Antonyms of unchallengeable controversial, debated, disputed; doubtful, dubious, iffy, inconclusive, indecisive, uncertain; ambiguous, equivocal; academic (also academical), hypothetical, speculative, theoretical (also theoretic)Antonyms of unchallengeable answerable, arguable, contradictable, controvertible, debatable, disputable, doubtable, moot, negotiable, problematic (also problematical), questionable, refutable