Related Clues:

• Fear
• Scare
• Frighten
• Auto option
• Morning waker-upper
• Apprehension
• Security concern
• It may do a number on your slumber
• Warning bell
• Eye opener, of a sort
• Chili-hotness measure
• Perturbation
• Snooze, for one
• It might scream after being tripped
• Eyeopener?