Related Clues:

• Geologic period
• Unbelievably long time
• It goes on and on
• Geologic time
• Longish time span
• 'Thou pleasing, dreadful thought,' to Addison
• L-o-n-g time period
• A really long time
• Long period
• A very long time
• 'It is the sea / Gone with the sun,' wrote Rimbaud
• It's a stretch
• Eternity
• Many eras
• Years and years and years and ...