dross Meaning, Definition & Usage

  1. noun worthless or dangerous material that should be removed
    impurity.
    • there were impurities in the water
  2. noun the scum formed by oxidation at the surface of molten metals
    slag; scoria.

WordNet

Dross noun
Etymology
AS. dros, fr. dreósan to fall. See Dreary.
Definitions
  1. The scum or refuse matter which is thrown off, or falls from, metals in smelting the ore, or in the process of melting; recrement.
  2. Rust of metals. R. Addison.
  3. Waste matter; any worthless matter separated from the better part; leavings; dregs; refuse.
    All world's glory is but dross unclean. Spenser.
    At the devil's booth are all things sold, Each ounce of dross coats its ounce of gold. Lowell.

Webster 1913