lockstitch I. \ˈ ̷ ̷ˌ ̷ ̷\noun Etymology:lock (II) + stitch : a sewing machine stitch formed by the looping together of two threads one on each side of the material being sewn II. transitive verb : to sew on or together with a lockstitch < lockstitching the border of the cuff > intransitive verb : to sew with a lockstitch < most modern sewing machines lockstitch >