lighter-than-air craft

1. 1.

   aircraft supported by its own buoyancy

   Broaderaircraft

   Narrowerairshipballoon

Questions about lighter-than-air craft

What does lighter-than-air craft mean?

lighter-than-air craft means "aircraft supported by its own buoyancy".

Is lighter-than-air craft a common word?

lighter-than-air craft is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.