Shirttail is a term used to describe the end of a shirt that hangs below the waistline. There are several synonyms for this word, including tail, hem, bottom, edge, and border. The tail is the backside of the shirt and the hem is the edge that is sewn to the lower part of the shirt. The bottom refers to the lower part of the shirt while the edge is the border that separates the shirt from the pants. The border is the area where the shirt and the pants come together. These synonyms are useful for describing different parts of the shirt and can help to add variety to your writing.