yuán​yuǎn​liú​cháng

long-standing

源远流长 (源遠流長) yuán​yuǎn​liú​cháng
long-standing idiom
having a long history and remote origins; literally describing a river with a distant source and long flow, and figuratively describing something that dates back to the distant past

Frequency

Written text
1.77 per million

Sources

Definitions
CC-CEDICT
Frequency data
BCC Corpus (BLCU)