veto (n.) Look up veto at
1620s, from Latin veto, literally "I forbid," first person singular present indicative of vetare "forbid, prohibit, oppose, hinder," of unknown origin. In ancient Rome, the "technical term for protest interposed by a tribune of the people against any measure of the Senate or of the magistrates" [Lewis].
veto (v.) Look up veto at
1706, from veto (n.). Related: Vetoed; vetoing.