Nisi Prius Law and Legal Definition

Nisi prius is a Latin term, meaning "unless the first". A nisi prius court is a court in which as case is first heard by as judge and jury, as opposed to an appellate level court. A nisi prius court is also called the "court of original jurisdiction" .

Under former English law, an issue was to be tried by a jury from the county of which the proceedings are dated, unless before the day appointed (nisi prius) the judges shall have come to the county in question (which they always do) and there try the cause. Nisi prius court judges became rarer as the travel demanded they travel longer distances.