A more thorough explanation:

Definition: Riens per descent (ryan pair day-sawn) is a legal term that means "nothing by descent" in Law French. It refers to the plea of an heir who is being sued for the ancestor's debt but did not receive any land or assets from the ancestor.

Example: Let's say John's father died and left behind a large debt. John is his only heir, but he did not inherit any property or assets from his father. If a creditor sues John for his father's debt, John can use the plea of riens per descent to argue that he did not receive anything from his father and therefore should not be responsible for his father's debt.

This legal term is important because it protects heirs who did not inherit any assets from being held responsible for their ancestor's debts. It ensures that only those who actually received something from the ancestor are held liable for their debts.