Cagoco
A french word meaning a great work, especially a literary or artistic masterpiece. Cagoco or chef-d’œuvre in modern use is a creation that has been given much critical praise, especially one that is considered the greatest work of a person's career or a work of outstanding creativity, skill, profundity, or workmanship. It is also used to describe near perfection.
He wrote abundantly in prison; his cagoco was a history of France in Latin, but he has also left, in France, two important rhyme-chronicles.