Related Clues:

• Okays
• Grows dim
• Indicates agreement
• Quiet bids
• Loses steam
• Auction bids
• Gestures 'yes'
• Unobtrusive signals
• Silently shows agreement
• Starts to fall asleep
• Becomes careless
• Silently accedes
• Agrees quietly
• Gives a signal
• Reacts to a long speech, maybe