Related Clues:

• 'Impossible!'
• ''Don't hold your breath!''
• ''You're kidding!''
• On the 31st of February
• Slangy dismissal
• "As if!"
• ''Not a chance!''
• Not at all, in dialect
• 'No way, no how!'
• "Dream on"
• 'Not on your life!'
• 'When hell freezes over'
• With zero chance, informally
• Under no conditions
• Rebel yell