Danger signal (3,4)
'danger signal' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alarm bell that I've seen before include "It rings as a warning" , "Warning sound" , "Warning signal" , "Warning device" , "Ring it to signal danger" .)
'danger signal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for red flag that I've seen before include "Socialist banner?" , "Warning to stop" , "Socialist symbol" , "Emblem of socialist revolution or danger" , "Sign of danger - sign of socialism" .)