Black dirt or soot, especially such dirt clinging to or ingrained in a surface.

污垢，灰垢黑色脏物或煤灰，尤指附着或深嵌在一个表面上的污垢。

youdao

Black dirt or soot, especially such dirt clinging to or ingrained in a surface.

污垢，灰垢黑色脏物或煤灰，尤指附着或深嵌在一个表面上的污垢。

youdao