Related Clues:

• Pigpen plaint
• Porcine protest
• Sign of a pen problem?
• Barnyard cry
• Chester White remark
• Sound on a 58-Across, perhaps
• Pen pal's protest?
• Swine sound
• Pig's sound
• Pigpen sound
• Swine squeal
• Sow's remark
• Reply to a pen pal?
• Pen word
• Pen parlance