“Boffo” is a relatively new word in English, first appearing in the American entertainment industry in the 1940s. As an adjective, “boffo” describes anything that is a smashing success or that generates uproarious laughter. The term was likely created from a mashup of “guffaw,” a type of laughter, and “buffo,” a certain type of comic opera actor. As the word got its start in showbiz, its usage mostly stays in reference to performances and entertainment.