zhā​zǐ

residue

渣滓 zhā​zǐ
residue noun
solid remains or dregs left after a substance has been processed or filtered

He carefully filtered the dregs out of the soup.

scum noun
worthless, contemptible, or disreputable people in society

This kind of social scum must be severely punished.

Frequency

Movie subtitles
1.91 per million appears in 1% of films
Written text
0.704 per million

Sources

Definitions
CC-CEDICT