unclean metal (e.g. dust, mud), especially when it is where it is not wanted (e.g. on the skin, clothes, in buildings)

grime, impurity

(a coating of) dirt on the surface of something or on the body

dirt

soft liquid mud, especially on a river-bed, the bottom of a pond, lake etc; (of moisture, thick liquid) to pass slowly through small openings

liquid emitted

any substance (e.g. sand, dirt) that settles on the bottom of a liquid

solid residue from liquid solution