A more thorough explanation:

Definition: Hereyeld is a term used in feudal systems to refer to the best animal (such as a horse, ox, or cow) that a vassal gives as tribute to their superior upon their death.

Example: In medieval Europe, a knight who served a lord would owe certain obligations, including providing military service and paying taxes. Upon the knight's death, their best animal would be given to the lord as a form of tribute. For example, if a knight had a prized horse, that horse would become the hereyeld.

Explanation: The example illustrates how the hereyeld was a form of tribute paid by a vassal to their superior upon their death. It was a way for the vassal to show their loyalty and respect to their lord, and for the lord to receive a valuable asset that could be used for various purposes, such as transportation or farming.