Scrap papers are rough or small pieces of paper that are no longer needed. Other words that can be used to refer to scrap papers are waste paper, discarded paper, and leftover paper. Waste paper refers to any material that has been deemed useless or discarded, including scrap papers. Discarded paper implies that the paper was intentionally thrown away. Leftover paper is paper that was not used and is of no value, and it can also refer to inconvenient scraps of paper that you find lying around. In summary, regardless of which synonym is used, all these words mean the same thing- scrap papers.