A more thorough explanation:

Definition: Feu duty, also known as ground annual, is the yearly rent paid by a tenant to the owner of a feu (a piece of land in Scotland).

Example: John owns a piece of land in Scotland and leases it to Sarah for 99 years. As part of the lease agreement, Sarah is required to pay John a feu duty of £500 per year.

Explanation: In this example, Sarah is the tenant and John is the owner of the feu. Sarah is required to pay John a yearly rent of £500, which is known as the feu duty or ground annual. This is a common practice in Scotland where land is often leased rather than sold outright.