Related Clues:

• Breathing problem
• Sleep disturber
• 'Get ___!' (boss's order)
• 'Step ___!'
• 'Get ___!'
• It's breath-taking
• 'Put a lid ___!'
• See 23-Across
• Sleep disorder
• Sleeper's woe
• 'I'll get right ___!'
• 'Don't bet ___!'
• Sleeper's breathing problem
• Sleep lab subject
• Volunteer's words