Backstitch is a strong hand stitch that doubles back on itself. Sew it in backstitch.
Each stitch goes back to meet the last one, so the line is unbroken like machine sewing. Backstitch is the strongest stitch you can do by hand and the slowest.
1nounbackstitchA strong hand stitch that doubles back on itself.
“She joined the seam in backstitch and it outlived the cloth.”
backstitch is a stitch.
Back plus stitch, from the needle going back on itself each time.
From back + stitch.
Etymology from Wiktionary, CC BY-SA