Related Clues:

• ''Hey, Mac!''
• Sign of agreement
• Call for attention
• O.K. sign
• Head-turner
• Sibilant exclamation
• Call to share a secret?
• Verbal nudge
• Attention-getter, in the audience
• ''Hey, you!''
• 'Can you keep a secret?'
• Approval of sorts
• Okay sign
• Utterance during a play
• O.K., say