Undeniable, a.
1. Not deniable; incapable of denial; palpably true; indisputable; obvious; as, undeniable evidence.
2. Unobjectionable; unquestionably excellent; as, a person of undeniable connections. [Colloq.] G. Eliot.
Shades of meaning
Fernald has no entry of its own for undeniable; he lists it under necessary.
He lists it without comment; the entries above explain its neighbors.