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"
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"
a device that signals the occurrence of some undesirable event
a clock that wakes a sleeper at some preset time
an automatic signal (usually a sound) warning of danger
eellike aquatic North American salamander with small forelimbs and no hind limbs; have permanent external gills
an acoustic device producing a loud often wailing sound as a signal or warning
a warning signal that is a loud wailing sound
a woman who is considered to be dangerously seductive
a sea nymph (part woman and part bird) supposed to lure sailors to destruction on the rocks where the nymphs lived; "Odysseus ordered his crew to plug their ears so they would not hear the Siren's fatal song"