A specific stitch used to cover and neaten the raw edges of the cut buttonholes; there is an easier buttonhole stitch which is very similar to blanket stitch and a true buttonhole stitch which has an added twist at the top; the thread is formed into a loop as the needle returns to the fabric.
Its main function is to make buttonholes, but it is also used for eyelets, embroidery and is a major stitch in needle lace work.