When it comes to dirigibles, there are a few other words that can be used interchangeably. One is airship, which is a more general term that encompasses all types of aircraft that use lighter-than-air gases for lift. Another synonym is blimp, which refers specifically to non-rigid airships with a streamlined shape. Zeppelin is another term that's often used synonymously with dirigible, although it technically refers to a specific type of rigid airship developed by the German company of the same name. Finally, some people use the term balloon to refer to dirigibles, although this is technically incorrect - balloons are completely non-powered aircraft that rely solely on the wind for propulsion.