一いっ生しょうに一いち度ど

expression, noun which may take the genitive case particle 'no'

once in a lifetime

Used for rare, special opportunities or experiences that may only happen once in one's life. Often modifies nouns with の.

• これは一いっ生しょうに一いち度どのチャンスだ。

  This is a once-in-a-lifetime chance.

• 一いっ生しょうに一いち度どの経けい験けんをした。

  I had a once-in-a-lifetime experience.