(DEVICE) [noun] [C] - a device for making a loud warning noiseIn big cities you hear police sirens all the time.The ship sounded its siren in the fog.The siren went off in the middle of the night to warn that there was going to be an air attack.
SIREN
Meaning of SIREN in English
Cambridge English vocab. Кембриджский английский словарь. 2012