ballonet

Definition

Any of several small balloons, inside a dirigible, that can be inflated or deflated to control buoyancy during flight.

Etymology

Borrowed from French ballonnet.

Example Sentences

• "An observation balloon, sausage-shaped and thickened at one end by small subsidiary ballonets, lifted itself, almost as though it were being hoisted by a series of pulls, out of one of the hollows beneath them […]."