also: やちとせ
noun
8000 years; thousands of years; eternity
Literally '8000 years', but often used hyperbolically to mean a very long time or eternity. The reading やちとせ is archaic/poetic.
八千年の歴史を誇る国。
A country boasting a history of 8000 years.
この伝統は八千年も続いていると言われる。
This tradition is said to have continued for thousands of years.
Compound of 八 (eight) + 千 (thousand) + 年 (year). The reading やちとせ uses the native Japanese reading や for 八 and ちとせ (千年) for 'thousand years', an older counting style.