- (literally) Air that has been heated, especially so as to function as the lifting agent of a hot-air balloon.
- The balloon was equipped with a burner to create hot air for lift.
- (idiomatic) Empty, confused, or exaggerated talk lacking meaning or substance; bluster.
1913, William MacLeod Raine, chapter 8, in The Vision Splendid:
- "You'll never get anywhere so long as youse trail with that reform bunch. It's all hot air and tomfool theory."
1921, Alice Hegan Rice, chapter 28, in Quin:
- "You give me a lot of hot air about your conscience. Why don't you get a soap-box and preach on the street-corners?"
- 2001 June 24, Johanna McGeary, "How Bad Is China?," Time (retrieved 22 Sept 2013):
- Some of the steam in Washington rises from real issues, but a lot is the hot air of partisan politics.
empty, confused or exaggerated talk