Related Clues:

• Mosque entranceway
• Callous cad
• Chemin de fer need
• Bridge piece
• Saarinen's St. Louis design
• One that gets tongue-tied?
• Height enhancer
• There may be a spat about it
• Type of string
• Keystone site
• Achilles' weak spot
• Aqueduct formation
• A real loafer
• Pump, perhaps
• Tongue-tied one?