1. a small air bag within a balloon or airship that can be inflated or deflated to control buoyancy and maintain shape
Usage: aeronautics

Examples

• The airship’s ballonet was inflated to compensate for the cooling gas.
• Engineers checked each ballonet before the dirigible’s maiden flight.
• The pilot adjusted the ballonet to maintain proper altitude.
• A punctured ballonet caused the balloon to lose its rigid shape.
• The ballonet system allows precise control of the aircraft’s buoyancy.