From the base of cheimon; a heap (as poured out), i.e. Rubbish; loose dirt -- dust.
see GREEK cheimon
STRONGS NT 5522: χοῦςχοῦς, χὠς, accusative χοῦν, ὁ (contracted for χὠς, from χέω, to pour), from Herodotus down;
1. properly, earth dug out, an earth-heap (German Schutt): ὁ χοῦς ὁ ἐξορυχθεις, Herodotus 2, 150.
2. dust (the Sept. for עָפָר): Mark 6:11; Revelation 18:19 ((Joshua 7:11; Wis. 5:15; Sir. 44:21, etc.); Plutarch, mor., p. 1096 b. (i. e. non posse suaviter etc. 13, 7)).