A more thorough explanation:

Definition: The power to decide for oneself or others; the power to decide finally and absolutely. The act of deciding or settling a dispute that has been referred to arbitration.

Example: When two parties cannot come to an agreement, they may choose to go to arbitrement to have a neutral third party make a final decision.

Explanation: In this example, the two parties are unable to come to a resolution on their own, so they turn to arbitrement to settle the dispute. The arbitrator has the power to make a final decision that both parties must abide by, which is the essence of arbitrement.