It also includes the authority a of formally constituted legal body or a political leader to deal with legal matters and , by implication , to administer justice within a defined area of responsibility . Jurisdiction ( from the Latin ius , iuris meaning `` oath '' and dicere meaning `` to speak '' ) is the practical authority granted to a formally constituted legal body or to a political leader to deal with and make pronouncements on legal matters and , by implication , to administer justice within a defined area of responsibility .