Related Clues:
- Warning bells
- Security measures
- "Emergency!" warnings
- Claxons
- They may have bells and whistles
- Firehouse ringers
- Warnings of danger
- Devices that signal danger
- Fills with apprehension
- Devices to signal danger
- Frightens, scares
- Frightens, makes afraid
- They signal danger
- Puts on guard or frightens
- Scares with warning devices