Drōss, n.
n. [A-S. dros, from dreosan, to fall, Goth. driusan; D. droes, droessem, A-S. drosn, O. H. Ger. drusen, dregs, Ger. druse, ore decayed by the weather, Icel. tros, rubbish, adulterated wares.]
Sense 1. The scum or extraneous matter of metals, thrown off in the process of melting; recrement.
Sense 2. An incrustation formed on metals by oxidation; rust; crust of metals. “A crust of dross.” Addison.
Sense 3. Waste matter; any worthless matter separated from the better part; impure matter; refuse.
All world's glory is but dross unclean. Spencer.