Related Clues:

• ''Heads up!'' e.g.
• Sound the alarm
• Far from drowsy
• Not asleep on the job
• Storm posting, e.g.
• Warning notice
• Like a sentry
• Bushy-tailed?
• Red __
• Word often preceded by a color
• Forewarn
• Blow the horn at
• Bring to the attention of
• On the lookout
• Like a watchdog