• A peculiar sort of stitch formed by the locking of two threads together, as in the work done by some sewing machines. See Stitch.
Lock' stitch` A peculiar sort of stitch formed by the locking of two threads together, as in the work done by some sewing machines. See Stitch . 
Type: Term Synonyms: locking suture
The basic stitch made by a sewing machine
a sewing-machine stitch in which two threads are locked together at small intervals.
This is the most usual and common type of stitching performed by sewing machines. A lock stitch is where two threads, one from the bobbin and one from the main thread are kept on their own side of the material, but literally ‘locked’ together each time the needle enters the fabric. The lockstitch is a secure stitch, that wont come undone once t...