A more thorough explanation:

Definition: Gazumping is a slang term used in British English to describe the improper sale of a house. This usually happens when a seller raises the price of the house after accepting an offer from a buyer. It can also occur when a competing buyer makes a higher bid than the one already accepted, causing the seller to back out of the earlier contract.

Example 1: John made an offer on a house for £200,000, and the seller accepted it. However, a few days later, the seller received a higher offer from another buyer and decided to sell the house to them instead. This is an example of gazumping.

Example 2: Sarah was in the process of buying a house when the seller suddenly raised the price by £10,000. Sarah had already paid for a survey and legal fees, but the seller refused to sell the house for the original price. This is another example of gazumping.

These examples illustrate how gazumping can be a frustrating and unfair experience for buyers who have already invested time and money into the buying process. It can also create a sense of distrust between buyers and sellers, making it harder for people to buy and sell houses in the future.