alarm
1. [ noun ] fear resulting from the awareness of danger
Synonyms: consternation dismay
Related terms: fear dismay unalarming alarming
2. [ noun ] a device that signals the occurrence of some undesirable event
Synonyms: alarm_system warning_device
Related terms: device burglar_alarm fire_alarm horn siren automobile_horn
3. [ verb ] fill with apprehension or alarm; cause to be unpleasantly surprised
Synonyms: appal appall horrify dismay
Examples:

"I was horrified at the thought of being late for my interview" "The news of the executions horrified us"

Related terms: frighten shock horror
4. [ verb ] warn or arouse to a sense of danger or call to a state of preparedness
Synonyms: alert
Examples:

"The empty house alarmed him" "We alerted the new neighbors to the high rate of burglaries"

Related terms: warn wake alert
5. [ noun ] an automatic signal (usually a sound) warning of danger
Synonyms: warning_signal alarum alert
Related terms: signal horn red_flag burglar_alarm siren fire_alarm foghorn tocsin air_alert torpedo
6. [ noun ] a clock that wakes sleeper at preset time
Synonyms: alarm_clock
Related terms: clock
Similar spelling:   alarmed
  alarmist
  alarmism
  alarming
  alarum