Safe call (3,5)
I believe the answer is:
all clear
'safe call' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for all clear that I've seen before include "Siren sound to mark end of bombing by planes" , "End-of-danger signal" , "Siren sound after air raid has ceased" , "safety announcement" , "Siren sound to signal end of air raid" .)