Indisputable, incontestable, unquestionable.
Insuperable, insurmountable.
Unequivocal; indubitable.
Containing instances of only one vowel; univocalic.
Having unison of sound, as the octave has in music.
Having only one possible meaning.
Having always the same drift or tenor; uniform; certain; regular.
A document containing instances of only one vowel.
A word having only one meaning.