jumbo [E19th] In the early 19th century jumbo was applied to a large and clumsy person. The word became well known when it was used as a name for an elephant at London Zoo. He was sold to the Barnum and Bailey circus in 1882, despite massive public protest. Jumbo had been known since the 18th century as the name of an African spirit, as in *mumbo jumbo. Since 1964 it has referred to a large jet airliner, in particular the Boeing 747.