Undeniable1. (a.) Not deniable; incapable of denial; palpably true; indisputable; obvious; as, undeniable evidence.
2. (a.) Unobjectionable; unquestionably excellent; as, a person of undeniable connections.
Thesaurus Entries
absolute, actual, admitting no question, arrant, authentic, classical, complete, confirmable, consummate, crass, de facto, decided, definitive, demonstrable, demonstratable, downright, egregious, factual, flagrant, for real, genuine, glaring, gross, historical, honest-to-God, inappealable, incontestable, incontrovertible, indisputable, indubitable, intolerable, irrefragable, irrefutable, out-and-out, outright, perfect, positive, precious, profound, pronounced, proper, provable, rank, real, regular, self-evident, shattering, shocking, stark, stark-staring, substantial, superlative, surpassing, testable, the veriest, thorough, thoroughgoing, total, TRUE, unanswerable, unbearable, unconfutable, unconscionable, unequivocal, unimpeachable, unmitigated, unqualified, unquestionable, unrefutable, unrelieved, unspoiled, utter, verifiable, veritable