dross / drôs; dräs/ • n. something regarded as worthless; rubbish: there are bargains if you have the patience to sift through the dross. ∎  foreign matter, dregs, or mineral waste, in particular scum formed on the surface of molten metal.DERIVATIVES: dross·y adj.

dross scum thrown off from metals in smelting OE.; dreggy matter, refuse XIV. OE. drōs = MDu. droes(e) dregs; cf. OE. drōsna (gen. pl.), MLG. drōsem, (M)Du. droesen(e) (Du. droesem), OHG. truosana (G. drusen) dregs, lees.