Grime is dirt that has built up in layers over time, creating a thick, greasy coating that's hard to remove. Fresh mud washes off easily and dust brushes away, but grime sticks stubbornly to surfaces because it's mixed with grease, moisture, and other sticky substances.

You'll find grime in places that get dirty regularly but aren't cleaned often: the grimy film on a kitchen stove from cooking oil and dust, the dark buildup between bathroom tiles, or the thick layer on windows that haven't been washed in months. Old factories, subway stations, and city buildings often show years of accumulated grime on their walls and windows.

The word captures something about neglect and time passing: a single spill doesn't create grime, but weeks or months of dirt slowly building up does. When something is described as grimy, it means it's coated with this stubborn, unpleasant layer of accumulated dirt. Removing grime usually requires serious scrubbing with strong cleaners, not just a quick wipe.

Grime can also describe a general state of dirtiness, like when your hands are covered in grime after working on a bicycle chain or exploring a dusty attic.