A more thorough explanation:

Definition: Vetus jus (vee-tus juss) refers to the law of the Twelve Tables in Roman and civil law. It can also refer to long-established or ancient law, or a law that was in force before the passage of a later law.

Example: An example of vetus jus would be the laws established in ancient Rome, such as the Twelve Tables, which were the foundation of Roman law. These laws were considered the basis of all later Roman laws and were used for centuries.

Explanation: The example illustrates how vetus jus refers to ancient or long-established laws. The Twelve Tables were created in 449 BC and were the first written laws in Rome. They covered a wide range of topics, including property rights, debt, and criminal law. These laws were considered the foundation of Roman law and were used for centuries, even after the fall of the Roman Empire.