The term 'sewer line' refers to a system of pipes that carries wastewater away from buildings and into a sewage treatment plant. The crossword solutions for this term are HEM (3 letters), SEAM (4 letters), THREAD (6 letters), STITCH (6 letters), and MAIN (4 letters). HEM is a folded edge of fabric, SEAM is a line formed by sewing two pieces of fabric together, THREAD is a thin strand of material used in sewing, STITCH is a loop of THREAD made by a needle in sewing, and MAIN is the primary or most important part.