unconstitutionalPronunciation: /ˌʌnkɒnstɪˈtjuːʃ(ə)n(ə)l/Translate unconstitutional | into French | into Italian Definition of unconstitutional adjective not in accordance with the political constitution or with procedural rules: they do not countenance unconstitutional action by the police the Act would be declared unconstitutional in the courtsDerivatives unconstitutionalityPronunciation: /-ˈnalɪti/ noun unconstitutionally adverb unconstitutional in other Oxford dictionaries Definition of unconstitutional in the US English dictionary