1.Definition: a clock that wakes a sleeper at some preset time

Category: Objects

2.Definition: a device that signals the occurrence of some undesirable event

Category: Objects

3.Definition: an automatic signal (usually a sound) warning of danger

Related Noun(s):alarum, alert

Category: General

4.Definition: fear resulting from the awareness of danger

Related Noun(s):consternation, dismay

Category: Feelings