ˌhot ˈair BrE AmE noun [uncountable]
things that someone says that are intended to sound impressive but do not really mean anything or are not true:
The theory was dismissed as a lot of hot air.
ˌhot ˈair BrE AmE noun [uncountable]
things that someone says that are intended to sound impressive but do not really mean anything or are not true:
The theory was dismissed as a lot of hot air.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012