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

See Examples For:

once in a lifetime

“This is Truly a once in a lifetime find,” Brown wrote on Instagram in January.

From Los Angeles Times ● Jul. 22, 2026

Female screwworm flies produce eggs only once in a lifetime, and once they mate with a sterile male fly, they’re done with their reproduction cycle without having any offspring.

From MarketWatch ● Jun. 10, 2026

He previously said the vest was "the only lifejacket from a survivor to emerge at auction in 114 years so it is literally a once in a lifetime opportunity for collectors".

From BBC ● Apr. 18, 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

My only regret is that I didn’t have a camera during the whole trip to capture this once in a lifetime opportunity.

From "The Freedom Writers Diary" by The Freedom Writers

Related Words

• unbelievable