The leftover solid bits at the bottom of a container after a liquid has been poured out.
After pouring the tea, only the dreg remained at the bottom of the cup.
お茶を注いだ後、カップの底には茶殻だけが残った。
The worst or least valuable part of something.
The dreg of society often faces the most hardship.
社会の滓はしばしば最も困難に直面する。
The least important or least capable members of a group.
Only the dreg of the applicants were left after the first round of interviews.
一次面接の後、応募者の中の滓だけが残った。