A more thorough explanation:

Exennium is a historical term that refers to a gift given at the new year.

• During the Roman Empire, it was customary to give exennium to friends and family on New Year's Day.
• In medieval Europe, lords would give exennium to their vassals as a sign of goodwill and loyalty.

These examples show how exennium was a common practice in different cultures and time periods. It was a way to show appreciation and strengthen relationships during the start of a new year.