A derby is a type of hat with a wide brim and high crown, typically made of straw or felt. It was popularized in the 19th century by Edward Coke, who wore it while attending horse races at Epsom Downs Racecourse near London, England. The name "derby" comes from the fact that these races were often referred to as "Derby Day." Over time, the term has come to refer to any major event or competition, especially those involving sports or horses.