Mil. [F., lit. ‘wolf-hole, wolf-pit.’] In field fortification, a conical pit with a pointed stake fixed vertically in the center, rows of which are dug before a work to hinder an enemy’s approach. Usually pl. trous-de-loup.
1789. Rees, Chambers’ Cycl., Trous-de-loup,… are round holes, about six feet deep, and pointed at the bottom, with a stake placed in the middle. They are frequently dug round a redoubt.
1828. J. M. Spearman, Brit. Gunner (ed. 2), 400. Trous-de-loup…. Diameter of the base, 4 feet 6 inches. Depth, 6 feet. Picket, 6 feet long.
1854. Bury & Norwich Post, 22 Nov., 4/4. Trous-de-loup are merely deep holes, in which men can lie and scramble in and out, but which are too broad and deep for a mounted man to cross.
1862. Catal. Internat. Exhib., II. XI. 14. This kind of obstacle would, on service, be found to occasion much more confusion than crows-feet, trous-de-loup, &c.
