Dross

The impurities of silver separated from the one in the process of melting (Prov. 25:4; 26:23; Ps. 119:119). It is also used to denote the base metal itself, probably before it is smelted, in Isa. 1:22, 25.

Part of speech: noun (n.)

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.