| adj. | 1. | (Aeronautics) Not rigid; especially, designating an airship having a shape maintained only by internal gas pressure and without a supporting structure. Opposite of |
| Adj. | 1. | nonrigid - designating an airship having a shape maintained only by internal gas pressure and without a supporting structure Antonyms: rigid - designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure |