Related Clues:

• It 'waits at the crossway of the stars,' wrote Borges
• Very long stretch
• Geologist's measure
• Memorable period
• Time on end
• Many, many moons
• Unit of Time
• Historic period
• Billion years, to a geologist
• Countless ages
• Millennia upon millennia
• It seems like forever
• Many centuries
• Millions of years
• Big time?