Related Clues:

• "Over here!"
• 'Hey ... over here!'
• Verbal elbow in the ribs
• Paying attention
• Subdued attention getter
• Furtive ''Hey, you!''
• Like sentries
• Sibilant summons
• ''Hey there''
• Alternative to 50-Across
• Like an excellent guard dog
• On top of things
• Not drowsy
• ''You there''
• Word with red or on