Definitions from Black's Law Dictionary: 2nd Edition and Ballentine's Law Dictionary as are available for each term in each dictionary.
  • Ballentine's Law Dictionary

    By virtue of (his) office.

  • Black's Law Dictionary: 2nd Edition

    From office; by virtue of the office; without any other warrant or appointment than that resulting from the holding of a partichlar office. Powers may be exercised by an officer which are not specifically conferred upon him, but are necessarily implied in hls office; these are ex officio. Thus, a judge has ex officio the powers of a conservator of the peace. Courts are bound to notice public statutes judicially and ex officio.
    —Ex officio information. In English law. A criminal information filed by the attorney general ex officio on behalf of the crown, in the court of king's bench, for offenses more immediately affecting the government, and to be distinguished from informations in which the crown is the nominal prosecutor. Mozley & Whitley; 4 Steph. Comm. 372-378.
    —Ex officio oath. An oath taken by offending priests; abolished by 13 Car. II. St. 1, c. 12.