ETYM Cf. Dan. grim, griim, lampblack, soot, grime, Icel. grîma mask, sort of hood, OD. grijmsel, grimsel, soot, smut, and Eng. grimace.
Dirt; any filthy matter, esp. if it is gritty and has been rubbed in or deeply ingrained.

To soil with grime or dirt deeply impressed or rubbed in.