Related Clues:

• On the lookout
• Like a watchdog
• Serve notice
• All-points bulletin
• In a post-caffeine state
• Premonish
• Like good guards
• All-points bulletin, e.g.
• Eagle-eyed
• Standing at the ready
• Sign word that may be followed by an exclamation point
• Shout "Fore!" to
• Shout "heads up!"
• Inform of danger
• Paying heed