alarm - noun

fear resulting from the awareness of danger

a device that signals the occurrence of some undesirable event

an automatic signal (usually a sound) warning of danger

a clock that wakes a sleeper at some preset time

alarm - verb

• fill with apprehension or alarm; cause to be unpleasantly surprised
• warn or arouse to a sense of danger or call to a state of preparedness

alarm - thesaurus

alarum   alert   appal   appall   consternation   dismay   horrify