Mappa Moon-day
This somewhat sardonic name for a magical artifact that’s over eight hundred years old is the sort of thing that you get when you don’t pay attention to what your grad students are doing. One jokester calls the item the “Mappa Moon-Day” at an absolutely critical moment during a sorcerous transport, and now that’s how it is defined by the universe. People have to call it that, if they want to activate the item at all.