Nisi prius (also called court of original jurisdiction) is a Latin phrase translated to “unless before” in English, and the term refers to disputes from a trial court or lower court in American law. Nisi prius cases are to be contrasted with those in a court of appellate jurisdiction that reviews decisions from the lower court. The modern American use of nisi prius stemmed from the term referring to local trials in England. Before the Magna Carta, all disputes in England must be tried where the dispute arose, and they often were required to be heard in London. After the Magna Carta, justices were sent throughout the country to hear matters locally which was given the term nisi prius.
[Last updated in August of 2021 by the Wex Definitions Team]