Scrap paper is a common name for pieces of paper that are no longer needed or have been used for a different purpose and are no longer useful. There are several synonyms for scrap paper, including waste paper, junk paper, leftover paper, and discarded paper. Waste paper is a term commonly used in the recycling industry, referring to paper that is thrown away instead of being recycled. Junk paper is a casual term used for scraps of paper that are useless and only take up space. Leftover paper refers to paper that is left over from printing or cutting. Discarded paper is paper that has been intentionally thrown away.