>>5I'm not too sure what you mean by 'other things', but our definition of pie is pretty much a baked pastry with a cover or casing, and the filling is pretty much up to you.
Our pies can be sweet or savory (maybe both?). Some pies have fruit and dessert fillings and are eaten for dessert, while other pies have fillings like chicken, and meat. Think of it like a crepe. It can be served sweet for dessert, or savory for breakfast/other meals.