A more thorough explanation:

Definition: Double forgery is a type of forgery where a document, such as a check, has both a forged signature from the person who is supposed to pay and a forged signature from the person who is supposed to receive the payment.

Example: John steals a check from his neighbor's mailbox and forges the neighbor's signature as the payor. He then forges his own signature as the payee and tries to cash the check at a bank. This is an example of double forgery.

This type of forgery is illegal and can result in serious consequences, such as fines and imprisonment. It is important to always verify the authenticity of a document before accepting or cashing it.