To take long, loose stitches over (the raw edges of a seam) to prevent raveling.
To fasten, as single sheets, by overcast stitching or by folding one edge over another.
A term used in repairing: when the ends of a rug are coming apart, the repairer uses a concealed whip stitch to prevent further unraveling.
a long whip stitch or overhand stitch overlying an edge to prevent raveling
sew over the edge of with long slanting wide stitches
sew with an overcast stitch from one section to the next; "overcast books"