Related Clues:

• Part of a box
• Falling-off point
• Part of a blade
• Polygon part
• Make sharper
• Defeat by a hair
• Good thing to have in competition
• ''Postcards From The ___''
• Competitive edge
• Borderline
• Rim … or trim
• Pole position, e.g.
• It can be the difference between winning and losing
• Sphere's lack
• Place for a fringe