Related Clues:

• Cover-up of astronomical proportions
• Cutoff point
• Exceed in importance
• Culmination
• Mortarboard
• See 34-Down
• Gown's go-with
• Stadium souvenir, perhaps
• See 4-Across
• Lens protector
• Upper limit
• The end of night?
• Bottle top
• Sun block
• Highest level