qiān​zǎi​nán​féng

rare

千载难逢 (千載難逢) qiān​zǎi​nán​féng
rare idiom
extremely rare; occurring only once in a long time, as if once in a thousand years

This is a once-in-a-lifetime opportunity; you must seize it.

Frequency

Movie subtitles
2.18 per million appears in 1% of films
Written text
1.30 per million

Sources

Definitions
CC-CEDICT