grime (grīm) n. Black dirt or soot, especially such dirt clinging to or ingrained in a surface. tr.v.
grimed, grim·ing, grimes To cover with black dirt or soot; begrime.
[Middle English grim; akin to Middle Dutch grīme; see ghrēi- in Indo-European roots.]
1590, probably alteration of M.E. grim "dirt, filth," from M.L.G. greme "dirt" (cf. Flem. grijm, M.Du. grime). The verb was earliest (as M.E. grymen, c.1470) but was replaced early 16c. by begrime.