If food is breaded, it has been covered in breadcrumbs — often dipped in egg or milk first so they stick — and then cooked, usually fried or baked. Menus say breaded chicken, breaded fish, breaded shrimp: crisp on the outside, soft inside. It is the -ed form of the verb to bread, which here does not mean to bake a loaf. It means to put crumbs on food.