Collins COBUILD Advanced Learner's English Dictionary - all clear

1. The all clear is a signal that a dangerous situation, for example an air raid, has ended. The all clear was sounded about 10 minutes after the alert was given. N-SING: the N • All clear is also a convention. ‘All clear,’ Misha growled. CONVENTION 2. If someone in authority gives you the all clear, they give you permission to continue with a plan or activity, usually after a problem has been sorted out. I was given the all clear by the doctor to resume playing. = go-ahead N-SING: the N