千せん年ねん

noun

thousand years; millennium; very long time

Literally a thousand years; also used figuratively for an extremely long time. The figurative use is common in expressions like 千年に一度.

• この神じん社じゃは千せん年ねん以い上じょうの歴れき史しがある。

  This shrine has a history of over a thousand years.

• 千せん年ねんに一いち度どのチャンスだ。

  It's a once-in-a-millennium opportunity.