ultra viresPronunciation: /ˌʌltrə ˈvʌɪriːz, ˌʊltrɑː ˈviːreɪz/Definition of ultra vires adjective & adverb Law beyond one’s legal power or authority: [as adjective]:jurisdictional errors render the decision ultra viresOrigin:Latin, literally 'beyond the powers'ultra vires in other Oxford dictionaries Definition of ultra vires in the US English dictionary