The Clue Get ___ of, as bread-crust to make a sandwich
The Answer RID
The answer "RID" fits the clue because it means to remove something. When making a sandwich, you might want to get rid of the bread crust to make it easier to eat. This action matches the idea of getting rid of something unwanted, like the crust. So, "RID" perfectly describes what you do with the crust in this context.