topstitch

From top +‎ stitch.

topstitch (usually uncountable, plural topstitches)

1. (sewing, uncountable) A sewing technique, most often used on garment edges such as necklines and hems, where it helps facings to stay in place and gives a crisp edge.
2. (countable) An individual stitch of this kind.

• topstitching

topstitch (third-person singular simple present topstitches, present participle topstitching, simple past and past participle topstitched)

1. (transitive) To stitch in this fashion.