Emily Dickinson Lexicon

DROSS, n. [Sax. dros; D. droes; G. druse, strangles, glanders; D. droessem, G. drusen, dregs; perhaps from rejecting or throwing off.]

1. The recrement or despumation of metals; the scum or extraneous matter of metals, thrown off in the process of melting.
2. Rust; crust of metals; an incrustation formed on metals by oxydation. – Addison.
3. Waste matter; refuse; any worthless matter separated from the better part; impure matter. The world's glory is but dross unclean. – Spenser.