Related Clues:

• Stiletto, e.g.
• Order to a dog
• It may fall on a foot
• Achilles's weak spot
• Part of a sock
• Half a McDonald's logo
• Keel over
• Command to a canine
• Dramatic entryway
• Instep, e.g.
• Supporting structure
• Span
• Foot shape
• St. Louis' Gateway, e.g.
• Lead-in for enemy