The term 'Book of Magic Spells' is often referred to as a Grimoire, which is an 8-letter word. A Grimoire is a book of magical instructions and spells that are used in the practice of magic. It is believed to have originated in the Middle Ages and is still used today by practitioners of various forms of magic. The Grimoire contains information on how to perform rituals, cast spells, and summon spirits. It also includes information on the history and mythology of magic, as well as advice on how to use the spells and rituals safely.