once in a lifetime

Idioms  

1. Extremely rare, especially as an opportunity. For example, An offer like that will come just once in a lifetime. This phrase, often used hyperbolically, was first recorded in 1854. Also see of one's life.

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Example Sentences

It is the only life jacket from one of the survivors ever to be put up for sale, with auctioneers describing the rare item as a "once in a lifetime opportunity for collectors".

From BBC • Apr. 15, 2026

The camaraderie among the crew and the teams supporting them on the ground, she said, was a once in a lifetime privilege.

From The Wall Street Journal • Apr. 11, 2026

“Once in a lifetime. Well, hopefully not once in a lifetime, but the first in a lifetime.”

From Los Angeles Times • Apr. 4, 2026

But what happened in Paris last spring might just have been once in a lifetime.

From The Wall Street Journal • Dec. 25, 2025

It was the kind of performance that came along once in a lifetime, and you didn’t want to miss one second.

From "Schooled" by Gordon Korman

Related Words

• unbelievable