Related Clues:

• Silent signal
• Yes, to a mime
• Furtive ''Yo!''
• Note passer's signal
• It's quick, supposedly
• Affirmative signal
• Nursery-rhyme angler
• Go out for a while
• Say yes, in a way
• Evince agreement
• Head-turning sound
• Clandestine call
• Get sleepy-eyed
• Near-silent 'Hey!'
• 'Hey … you!'