Related Clues:

• Subtle attention getter
• "Hey, you!"
• Furtive whisper
• [Look over here!]
• Sotto voce call
• Subtler alternative to 'Yo!'
• "Hey you!"
• 'Hey, buddy'
• Sound from an exam cheater
• "Want to hear a secret?"
• Listen!
• Verbal jab in the ribs
• 'You there!'
• "Hey, Mister!"
• Clandestine signal