Related Clues:

• Sound of disapproval
• Unexpectedly come (by)
• See 58-Down
• Mah-jongg piece
• Explode
• Fizzy drink
• 'Pow!'
• Greeting for the villain
• See 6-Down
• Comic book punch sound
• Appear, with 'up'
• 30-Down, informally
• Bad sound for a balloonist
• Halloween greeting
• It may give you a good start