Definition from Wiktionary, the free dictionary
- (idiomatic) That which happened a long time ago and not worth discussing any more.
- Who cares if he said those things at the beginning of the year? That's ancient history now.
- A period of history generally seen as occurring before the Middle Ages, that is, before the fall of the Roman Empire. Includes Ancient Egypt, Ancient Greece and Ancient Rome.
not worth discussing any more
period of history