Related Clues:

• Frightens or alerts
• Frightens like warning devices
• Frightens and startles
• Alerting devices - burglars?
• Warning clocks that wake us up
• Scares or startles
• Scares, hopefully burglars
• Causes fear
• Half a hundred limbs? That's a frightful lot.
• After 4 down, they go on ahead or on the canal, perhaps
• A half a hundred frightfully handy things
• You should not sleep through them, by the sound of it
• Half a hundred limbs that won't put me to sleep
• They go off as Albert gets ready to fight
• How frightful when Albert prepares to fight!