dross

dross is a   Noun

Definition:

[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.

Synonyms: