n A long black mark left on a road surface from the sliding or skidding tires of a motor vehicle that has lost traction.
n Any other mark or stain caused by one surface skidding along another.
n (colloquial|humorous|euphemistic) A visible feces stain left on underpants, trousers, or sometimes the toilet bowl ; the mark of a soiledfingerwiped on a surface.
n Any burn on the skin caused by scraping the skin against a surface.