A more thorough explanation:

"Frustration of purpose" is a legal term used in contract law. It means that if a buyer enters into a contract with a seller for a specific purpose, but an unforeseen event happens that makes it impossible for the buyer to achieve that purpose, then the buyer can be excused from performing their duties under the contract.

For example, let's say a farmer enters into a contract with a grain seller to buy a certain amount of grain at a certain price. The farmer's purpose for buying the grain is to feed their livestock. However, a drought occurs and the grain seller is unable to produce the amount of grain they promised. In this case, the farmer can use the frustration of purpose doctrine to excuse their performance under the contract.

Another example could be a company that enters into a contract with a venue to host a conference. However, due to a natural disaster, the venue is destroyed and cannot be used for the conference. In this case, the company can use the frustration of purpose doctrine to excuse their performance under the contract.

These examples illustrate how the frustration of purpose doctrine can be used to protect buyers from unforeseen events that make it impossible for them to achieve their purpose for entering into a contract.