A more thorough explanation:

Definition: A handsale is a historical term used to describe a sale that was confirmed by shaking hands. It was a way of sealing a deal between two parties. Over time, handsale also came to refer to the earnest money given immediately after the handshake. In some northern European countries, shaking hands was necessary to bind a bargain. This custom sometimes persists for oral contracts. The Latin phrase for handsale was venditio per mutuam manuum complexionem (“a sale by the mutual joining of hands”).

Example: In the past, when people wanted to buy or sell something, they would shake hands to confirm the deal. For example, if a farmer wanted to sell his cow to a neighbor, they would agree on a price and then shake hands to confirm the sale. The buyer would then give the seller some money as a deposit, which was called handsale.

Explanation: The example illustrates how handsale was used in the past to confirm a sale between two parties. The handshake was a way of sealing the deal, and the handsale was the deposit given by the buyer to the seller to show that they were serious about the purchase. This custom was common in northern European countries and was a way of binding a bargain.