The term 'ARBITER WITH A WHISTLE' is a job description for a referee, which is a three-letter acronym of 'REF'. A referee is an official who presides over a sporting event and enforces the rules of the game. They are usually identified by their distinctive uniform and whistle. Referees are responsible for making sure that the players abide by the rules and regulations of the sport, and they have the authority to issue warnings, penalties, and ejections when necessary.