veto: [17] Latin vetō meant ‘I forbid’ (it was the first person present singular of vetāre ‘forbid’, a verb of uncertain origin which may be related to Welsh gwadu ‘deny’). It was used in the Roman senate by tribunes of the people as a formula for objecting to proposals, and it was originally introduced into English as part of the terminology of parliamentary procedure. [veto etymology, veto origin, 英语词源]