jury

N. A group of citizens picked according to law and authorized to decide the facts of a case

civil ~ (US) - trier of fact in civil cases such as negligence, fraud. (In the U.K. a civil jury exists only for cases of libel and slander, fraud, malicious prosecution, and false imprisonment.)

criminal ~ - trier of fact in criminal cases

grand ~ - body of citizens that determines whether probable cause exists that a crime has been committed and whether an indictment should be issued

juror

N. - a member of a jury