A more thorough explanation:

Definition: Wardite is a historical term that refers to a fine that a tenant had to pay if they failed to fulfill their duty of castle-guard. Castle-guard was a duty where tenants were required to protect a castle or fortress.

Example: If a tenant was assigned to castle-guard duty and failed to show up or neglected their duty, they would be charged a wardite fine.

Explanation: The example illustrates how wardite was used as a penalty for failing to fulfill the duty of castle-guard. It was a way to ensure that tenants took their responsibilities seriously and protected the castle or fortress they were assigned to guard.