A more thorough explanation:

Definition: An officer of the royal mint who tests bullion taken in for coining. This position was established by St.2 Hen. 6, ch. 12.

Example: When someone brings in gold or silver to be turned into coins, the assayer of the king is responsible for testing the purity of the metal. They use various methods to determine the amount of precious metal in the bullion, such as melting it down and analyzing the composition. This ensures that the coins produced by the mint are of a consistent quality and value.

Explanation: The example illustrates how the assayer of the king plays a crucial role in the minting process. By verifying the purity of the bullion, they help maintain the integrity of the currency and prevent fraud. This position was particularly important in the past when coins were made of precious metals like gold and silver, which could be easily debased by adding cheaper metals. Today, most coins are made of base metals like copper and nickel, but the role of the assayer is still important in ensuring that the coins meet certain standards of quality and accuracy.