Late Latin 'univocus' (one voice) — the direct antonym of 'equivocal,' a term with exactly one meaning.
Having only one possible meaning; unambiguous; (in logic) a term used in exactly the same sense in every instance.
From Late Latin ūnivocus (having one voice, signifying one thing only), from Latin ūnus (one) + vōx (voice; genitive vōcis). The element ūnus derives from PIE *óynos (one, single), ancestor of English one, alone, atone, and none. The element vōx derives from PIE *wokʷ- (voice, to speak), which also gives Latin vocāre (to call), vōcālis (vocal),
In medieval Scholastic philosophy, the question of whether the word 'being' is univocal (meaning the same thing when applied to God and to creatures) or equivocal (meaning different things) or analogical (meaning related but not identical things) was one of the central debates. Duns Scotus argued for univocity; Thomas Aquinas argued for analogy. The debate shaped centuries of Western theology and metaphysics, all hinging on whether one Latin word could speak with one voice or must always speak with several.