nisi prius

[ nahy-sahy prahy-uh s, nee-see pree-uh s ]
/ ˈnaɪ saɪ ˈpraɪ əs, ˈni si ˈpri əs /

noun Law.

Also called nisi prius court. a trial court for the hearing of civil cases before a judge and jury.
British Law.
  1. a writ commanding a sheriff of a county to summon a jury and bring it to the court in Westminster on a certain day, unless the judges of assizes previously came to that county.
  2. the clause with the words “nisi prius” introducing this writ.
  3. the system of judicial circuits to which judges are assigned for local trials of civil and criminal cases.

Origin of nisi prius

1300–50; Middle English < Latin: literally, unless previously, unless before

Related forms

ni·si-pri·us, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for nisi prius

nisi prius

/ (ˈpraɪəs) /


English legal history
  1. a direction that a case be brought up to Westminster for trial before a single judge and a jury
  2. the writ giving this direction
  3. trial before the justices taking the assizes
(in the US) a court where civil actions are tried by a single judge sitting with a jury, as distinguished from an appellate court

Word Origin for nisi prius

C15: from Latin: unless previously
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012