Related Clues:

• Alphabetic character
• Alphabet character
• Architectural feature
• Corner letter?
• Wing, perhaps
• Extra room, perhaps
• Cockney's perdition
• Angled extension
• Shape of a right angle
• 90-degree shape
• Angular addition
• Plumbing joint
• Old Nick's 'eadquarters?
• 90-degree angle
• Pipe with a bend