The term "bottom sheet" is commonly used to refer to the fitted sheet that covers the mattress. However, there are many synonyms that can be used to describe this piece of bedding. Some of them include fitted sheet, bottom linen, mattress cover, fitted bedspread, bedsheet, and bottom fabric. Each of these synonyms describes the same piece of bedding that is used to protect the mattress and provide a comfortable sleeping surface. The choice of synonym often depends on personal preference or regional variations. Regardless of the term used, the bottom sheet is an essential part of any bedding set and ensures a good night's sleep.