vbl. sb. Mil. [? f. SPIT sb.3] (See quots.) Also Spit-lock v.
1834. J. S. Macaulay, Field Fortif., iii. 49. Having set up the profiles, trace with a pick-axe (note Termed ‘spit-locking’) the escarp and counterscarp lines.
1892. G. Philips, Text Bk. Fortif. (ed. 5), 153. Cutting a groove along the surface of the ground with the point of a pick (spit-locking). Ibid., 154. The bounding lines of the parapet … may be spit-locked.
