Related Clues:

• Spilling point
• It runs around a bowler
• Overflow site
• Panama border?
• Cup edge
• Edge of a hat
• Hat edge
• Boater feature
• Glass top
• Tipping point?
• Top of the glass
• Sombrero part
• Overflow, with ''over''
• A cowboy hat has a wide one
• Teacup part