A more thorough explanation:

Definition: An exchanger of lands; a broker.

Example: In medieval times, an excambiator was a person who facilitated the exchange of lands between two parties. They acted as a broker, negotiating the terms of the exchange and ensuring that both parties received fair value for their property.

Explanation: The example illustrates how an excambiator was a person who helped people exchange lands. They were like a real estate broker who helped people buy and sell property. The excambiator would negotiate the terms of the exchange and make sure that both parties received a fair deal. This was important in medieval times when land was a valuable commodity and disputes over property could lead to conflict.