Related Clues:

• One-word advice
• 'Cut that out!'
• 'Can it!'
• Shut down
• Stop order?
• Cut out
• Fire starter?
• Halt
• Pull the plug on
• Parental command
• Cautionary advice
• Middle of the quip, with 37-Across
• 'Cut it out!'
• 'Quit it!'
• Stop it