niú​sōu​mǎ​bó

base materials

牛溲马勃 (牛溲馬勃) niú​sōu​mǎ​bó
base materials
seemingly useless or lowly items, like cow urine and horse-puffball fungus, that nevertheless have their own specific uses
worthless nonsense idiom
insignificant or worthless things, especially referring to low-quality writing or trivial matters

Frequency

Written text
0.001 per million

Sources

Definitions
CC-CEDICT
Frequency data
BCC Corpus (BLCU)