|Origin:||alarme, from Old Italian all' arme 'to the weapon'|
a piece of equipment that makes a loud noise to warn you of danger
a burglar/fire/smoke alarm
I forgot to set the burglar alarm.
He set off the alarm (=made it start ringing) by accident.
The fire alarm's going off (=it is ringing).
a sophisticated alarm system
a feeling of fear or worry because something bad or dangerous might happen
There is growing alarm at the increase in crime.
She looked up in alarm.
Scientists have said there is no cause for alarm.
an alarm clock:
I've set the alarm for 7 o'clock.
I was still asleep when the alarm went off.
4 especially British English
to warn people that something bad is happening:
Neighbours raised the alarm when they smelled smoke.
if alarm bells ring, you feel worried that something bad may be happening:
Alarm bells started to ring when he failed to return home.