A more thorough explanation:

Definition: A privy seal is a type of seal that is used to make grants or letters patent before they are passed under the great seal. It can also refer to the position of Lord Privy Seal.

Example: When the king wants to grant a title or land to someone, he first uses a privy seal to make the grant official. This seal is then passed under the great seal to make it legally binding.

Explanation: The example illustrates how a privy seal is used to make official grants or letters patent. It shows that the privy seal is an important step in the process of making a grant legally binding.