How to sign: the state of being covered with unclean things
Similiar / Same: grime, soil, grunge, dirt, filth, grease
Categories: dirtiness, uncleanness
How to sign: make dirty or spotty, as by exposure to air; also used metaphorically
"The silver was tarnished by the long exposure to the air"; "Her reputation was sullied after the affair with a married man";
Similiar / Same: tarnish, maculate, sully, defile
Categories: blob, blot, fleck, spot
Within this category: darken