'veto' originates from Latin, specifically the word 'vetō' (first-person singular present of 'vetāre'), where the root meant 'to forbid'.

'veto' passed from Latin (vetō / vetāre) into English in the early 17th century, retaining much of its original form and meaning; it was used in English in political and legal contexts from the start.

Initially it was literally the Latin 'I forbid' (a verbal form), and over time it developed into both a noun meaning 'an authoritative refusal' and a verb meaning 'to refuse or prohibit'; the core sense of forbidding has remained.