Historic (adjective)

1. Relating to history, especially to the study of history.
2. Important or significant in history.
3. Having great and lasting importance.

Origin:

Late middle english: via old french from latin historicus, from historia (see history).

Examples:

1. The building is of historic significance.
2. This is a historic moment for our country.
3. He made a historic breakthrough in the field of medicine.
4. This is a historic opportunity for peace.
5. The battle was a historic defeat for the enemy.