Related Clues:

• 'No, you're not' retort
• Tough nut to crack
• Rebuttal to 'No, you're not'
• Playground affirmation
• Tough one
• "Cheese" sayer
• Tough problem
• It's not easy
• 1993 Melissa Etheridge album and song
• Affirmative reply
• Puzzling problem
• Show-off
• Difficult problem
• Difficult puzzle
• Sticky problem