The term Jumbo Flier is a combination of two words, JET and Jumbo. JET is a type of aircraft that is powered by JET engines and is capable of reaching high speeds. Jumbo is a term used to describe something that is very large in size. Therefore, the term Jumbo Flier refers to an aircraft that is powered by JET engines and is very large in size. This type of aircraft is typically used for long-distance travel and can carry a large number of passengers.