Arbitration is the process of judging officially how an argument should be settled — the meetings, the rules, and the decision — usually without a full court case. Two companies, or a worker and a boss, go to arbitration. A contract often already says “if we fight, we use arbitration.” It is a formal, legal-sounding noun. People mix it up with mediation. In mediation, a helper tries to get both sides to agree. In arbitration, someone decides, and that decision usually sticks. Though actually, some arbitration is binding (you must follow it) and some is not; the word by itself does not always tell you which. You go to arbitration; you do not “do an arbitration” in casual talk the way you “do a meeting,” though lawyers will speak of “an arbitration.”