Related Clues:

• Golden and Bronze, e.g.
• Gets better?
• Several eras
• Sentence units, often
• Shakespeare's seven
• Loses immediacy
• It's quite a stretch
• Word on a toy package
• Billing units
• Oodles of time
• Incredibly long time
• Proterozoic or Archeozoic, e.g.
• Period of many years
• Extremely long time
• Who-knows-how-long