Related Clues:

• State of (sudden) fear
• Chili hotness unit?
• Early buzz?
• There's usually no cause for this
• Cellphone feature
• It might hold up a holdup
• Siren or bell
• See 9 Across
• More than startle
• It might stop a burglar
• Great concern
• *Frighten
• It'll put you on guard
• Fill with apprehension
• Startle, frighten