Related Clues:

• 'That's bad!'
• 'Tsk tsk' relative that is only different by four letters
• Disappointed sound
• Vowelless reproach
• What might be heard with a head shake
• Vowelless interjection
• 'Bad!' sound
• Reaction to a 71-Across
• It might accompany the wag of a finger
• 'Shameful!'
• [That was bad of you!]
• "Shame!"
• "For shame!" sound
• "You messed up"
• 'You messed up'