- (countable) An alarm is a signal that something needs attention or a machine that makes the signal.
- I wake up, without an alarm clock, at seven or eight a.m.
- People in the restaurant ran out the emergency exit, sounding the alarm.
- The safety system was known to be defective and had frequently sent out false alarms.
- The hotel did not have fire alarms or a sprinkler system.
- A fire in the fry pan set off the smoke alarm.
- (uncountable) Alarm is a feeling of worry or fear.
- They watched with some alarm as the speeding car got closer.
- This is completely natural and no cause for alarm.
- (transitive) If you alarm someone, you make them feel worried or scared.
- The school was alarmed by the number of children failing math.