My understanding is that when talking about aircraft, "lighter-than-air" means that it's designed to require no additional lift to keep it aloft regardless of c

My understanding is that when talking about aircraft, "lighter-than-air" means that it's designed to require no additional lift to keep it aloft regardless of cargo. Anything requiring non-aerostatic lift would be considered a hybrid. https://en.wikipedia.org/wiki/Aerostat https://en.wikipedia.org/wiki/Aerostat