Related Clues:

• Significant period
• Longish time span
• Time immemorial
• L-o-n-g time period
• Period of note
• A really long time
• Long period
• A very long time
• Distinctive period of history
• It's a stretch
• Eternity
• Many eras
• Years and years and years and ...
• Near-eternity
• Lo-o-ong time