What does "all clear" mean?

a signal that danger, such as an air raid, is over; usually a siren at a single pitch

What is a synonym for "all clear"?

Common synonyms include: above water, air-raid alarm, alarm, alarm bell, alarm clock, alarm signal.

noun

noun ·Uncommon ·Advanced level

Noun

1
a signal that danger, such as an air raid, is over; usually a siren at a single pitch countable, uncountable
2
permission to proceed because obstacles have been removed wordnet
3
permission to proceed after obstacles have been removed countable, uncountable
4
a signal (usually a siren) that danger is over wordnet

all + clear