Related Clues:

• Bob of hope, maybe
• Doze momentarily (with "off")
• Fall asleep (with "off")
• Agree wordlessly
• Signal of approval
• Drowse
• Bobbleheads do it
• Approval of a sort
• Assent wordlessly
• Head-moving assent
• Nomination, so to speak
• Say "yes" without saying it
• Bid silently
• Assent of a sort
• Exhibit drowsiness