a burglar/car/fire/smoke alarm
to set off an alarm
It turned out that the fire alarm had gone off and they had to evacuate the building. (First Certificate in English; B2; Greek)
The alarm went off at 5.30 and she got up immediately.
Suddenly the alarm started to ring and I woke up to go to school. (Preliminary English Test; B1; Spanish)
There's no need for alarm - it is completely safe.
Fortunately, her soothing voice damped down any sense of alarm. (Certificate of Proficiency in English; C2; Spanish)
Her parents raised the alarm when she failed to return home.
A local doctor was the first to raise the alarm about this latest virus.
For them, raising the alarm because of five percent unemployment is an example of so-called 'loony-left thinking'. (Certificate of Proficiency in English; C2; Polish)
I don't want to alarm you but he really should be here by now.
What alarmed us the most was the daring use of speculation by the author. (Certificate in Advanced English; C1; Spanish)