Related Clues:

• ___ John
• 'Nuts!'
• Refuse
• Emphatic denial
• 'Gotcha!'
• Vocalist John
• 'Yeah, right!'
• 'Phooey!'
• 'I knew it!'
• 'Darn!'
• Nonsense
• Cynic's retort
• 'When pigs fly!'
• See 50-Across
• Twaddle