alarm

nouns

fear resulting from the awareness of danger

alarm, consternation, dismay

a device that signals the occurrence of some undesirable event

an automatic signal (usually a sound) warning of danger

alarm, alarum, alert, warning signal

a clock that wakes a sleeper at some preset time

alarm, alarm clock

fill with apprehension or alarm; cause to be unpleasantly surprised

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

alarm, appal, appall, dismay, horrify

is derived from

warn or arouse to a sense of danger or call to a state of preparedness

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

alarm, alert