The word "ref" is often used as an abbreviated form of "referee" in sports and other competitive environments. However, there are many synonyms for this word that can be used to convey the same meaning. These include umpire, official, judge, arbiter, adjudicator, mediator, and overseer. Each of these words has slightly different connotations, and the choice of synonym will depend on the context in which it is used. In general, these synonyms all refer to someone who is responsible for ensuring that rules are followed and that the participants in a competition or debate are treated fairly.