The term DRESS LINE refers to the stitching that is used to construct a dress. The two crossword solutions, SEAM and HEM, refer to two different types of stitching used in dressmaking. A SEAM is a line of stitching that joins two pieces of fabric together, while a HEM is a line of stitching that finishes the edge of a piece of fabric. Both are essential components of dressmaking and are used to create the dress line.