all clear

English Thesaurus

1. permission to proceed because obstacles have been removed (noun.communication)

hypernym	:	permission,
definition	:	approval to do something (noun.communication)

2. a signal (usually a siren) that danger is over (noun.communication)

hypernym	:	sign, signal, signaling,
definition	:	any nonverbal action or gesture that encodes a message (noun.communication)