Possible Clues:

• Insistent reply
• Part of a playground volley
• 'I __ busted!'
• 'Are not!' evoker
• 'I ___ Proud' ('The Mikado' song)
• ''I __ out of here!''
• 'Are not!' rejoinder
• Child's response to "Are not!"
• Recess rejoinder
• Adamant affirmation