Related Clues:

• Speech problem
• Have trouble with esses
• Daffy Duck's impediment
• Challenge for a speech coach
• Repeat oneself?
• Struggle with one's silly sisters?
• Stammer a la Porky
• Saying 'th' for 's'
• Suffer with sibilants
• Talk like th-th-this
• Talk like thith
• Topic in speech therapy
• Thpeak like thith
• Talk like Daffy
• Subject for a speech therapist