ˌfalse ˈdawn BrE AmE noun [countable] formal
a situation in which something good seems likely to happen, but it does not:
The ceasefire turned out to be another false dawn.
ˌfalse ˈdawn BrE AmE noun [countable] formal
a situation in which something good seems likely to happen, but it does not:
The ceasefire turned out to be another false dawn.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012