The term "single stitch" refers to a basic and versatile stitch used in sewing and embroidery. However, there are several synonyms that can be used to describe this stitch, depending on the context. Some common synonyms for single stitch include running stitch, straight stitch, and basic stitch. These terms all describe the same basic technique of pulling a needle and thread through fabric in a straight line. Other variations of the single stitch include backstitch, whipstitch, and ladder stitch. Depending on the project and desired outcome, different types of single stitch may be used to achieve the desired result.