Related Clues:

• -- rule (usually)
• Ice or Iron
• Pale -- ghost
• Hard-rock center?
• Get gray
• See 66A
• It's 'just a number'
• Simile connector
• High-kite link
• Golden, for one
• What the number of birthday candles signifies
• Yours gets a yearly increase
• Go gray, say
• ---
• Cause of some lines