A sign or signal indicating that a hindrance or danger is clear.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "all-clear" in a sentence
"To be sure, investors aren't ready to call the all-clear on the myriad challenges still facing the global economy, from soaring oil prices, political instability across the energy-exporting Middle East, and nuclear risks after this month's Japanese earthquake."
"They seemed almost cartoonish with their silly, different-colored “terror alerts” that had done little except raise fears only to call the all-clear with no explanations…sort of like the boy who cried wolf."
"He’d just called an all-clear on the third bomb in less than two minutes, but the first one had cost nine."