1. to act as arbiter upon (a disputed question) : to settle (a dispute between two people or groups) after hearing the arguments and opinions of both. To make an official decision that ends a legal disagreement between people or groups without the need for the disagreement to be solved in court.(2) "Arbitrator" means an individual appointed to render an award, alone or with others, in a controversy that is subject to an agreement to arbitrate. Arbitration is a formal method of dispute resolution involving a third party neutral who makes a binding decision. 44.1011 Definitions. Find the complete AAA's StepbyStep Guide to Arbitration Filing, covering all aspects of arbitration including ICSID and ICC, in English. Arbitration is a method used to resolve legal disputes.