Shorthand for "demeaning cinematic image of blacks"; it comes from the stage name of actor Stepin Fetchit. He worked in films of the 30s and 40s as a stereotype-on-two-legs: craven, lazy, subservient, shufflin'. He wasn't alone, but he gained the most fame. In later decades, he got a chance to play decent roles. Ever since the TV adaptation of Amos and Andy got cancelled amid protests (valid or not), black stereotypes have become more politically correct, but stereotypes remain.