Related Clues:

• Dormancy
• Signal at Christie's
• Start to nod off
• Nonverbal 'yes'
• "Nature's soft nurse," to Shakespeare
• A bed habit
• "Go ahead" signal
• Dream on?
• Nonverbal assent
• Indication of a green light
• Acknowledge silently
• Use your head positively?
• Wordless OK
• Wynken and Blynken's companion
• Why isn't one done?