As used by the airlines, an extensible walkway that is articulated and usually enclosed. It kind of looks like a stretched out accordian from the outside. It is positioned so that passengers can walk from the terminal building to the door of the aircraft in comfort and safety.
The passengers walked down the jetway to board their flight to Norway.
A flying vehicle. It is often a type of dirigible, such as a blimp.
A ship that flies.
They can be found in some role-playing games such as Final Fantasy, and are flying vehicles that seem to use a combination of aerodynamic principles and magic.
I was very excited when I first acquired the Airship in Final Fantasy 1, it made my travels much easier and more fun. The airship travels at four times walking speed across the world map. That seemed very fast to me at the time.