residue or sediment left over after something useful has been extracted

sediment; dregs; solid matter that settles at the bottom of a liquid; (figuratively) the dregs of society

literal dirt, mud, or dust

dirt; filth; any dirty or impure matter

scum of society; the dregs of society; scourings

husks and chaff; refuse

sediment or residue left over from brewing wine or distilling spirits