Definition - What does Arbitrator mean?
The term "arbitrator" can simply be defined as a person who conducts an arbitration. It refers to the person who performs their duties as a judge and conducts a mini-trial, which is considered to be a little less formal than a court trial.
In most cases, an arbitrator is either an individual attorney or part of a panel.
Justipedia explains Arbitrator
Under most jurisdictions these days, courts have a full list of attorneys working as arbitrators. Other than that, there are professional arbitration services like the American Arbitration Association, which has a panel of working attorneys chosen by the Association to act as arbitrators.