Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun dross

2 senses of dross

Sense 1
impurity, dross -- (worthless or dangerous material that should be removed; "there were impurities in the water")
       => waste, waste material, waste matter, waste product -- (any materials unused and rejected as worthless or unwanted; "they collect the waste once a week"; "much of the waste material is carried off in the sewers")

Sense 2
slag, scoria, dross -- (the scum formed by oxidation at the surface of molten metals)
       => scum -- (a film of impurities or vegetation that can form on the surface of a liquid)