Gasbag

In half an hour a good-sized gas-bag had been formed, and the jerking and straining upon the thongs showed that it was capable of considerable lift.

Source: wiktionary

By this method of construction a considerable amount of support can be imparted to the gasbag, though it does not dispense with the services of the ballonet, as does the entirely rigid type.

Source: wiktionary

A novel robotic gasbag polishing technique based on flexible polishing principle has been presented by S.M. Ji et al., which can make polishing process more stable and effective because the rubber gasbag provides cushioning action and almost all abrasive particles in the contact area are involved in the process of material removal on mould surface, etc […]

Source: wiktionary

Not that the Reverend James is absolutely a pretentious gasbag any more than Marchbanks is an inspired prophet. He has a definite, a positive part in the world's work.

Source: wiktionary