gasbag

Noun

gasbag (plural gasbags)

1. A bag or bladder to hold a reservoir of gas, as in a hot-air balloon.
   • 1914: Eric Henry Stuart Bruce, Aircraft in War [1]

     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.

2. Metaphorically, a person who is overly garrulous or prone to making empty, unsupportable statements.
   • 1911: Edward Everett Hale, Dramatists of To-day: Rostand, Hauptmann, Sudermann, Pinero, Shaw, Phillips, Maeterlinck [2]

     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.

Synonyms:

• blowhard (sense 2)
• windbag (both senses)