1851 J. S. Macaulay Treat. Field Fortif. 105 The object of defilade is so to regulate the relief of the parapets or covering masses, that the defenders may be perfectly screened by them from the view of the enemy.

1851 J. S. Macaulay Treat. Field Fortif. 111 It often happens..that a single plane of defilade would give too great a relief.

1855 Portlock in Encycl. Brit. IX. 801/2 It is preferable to excavate behind the parapet, whenever the defilade requires so great an increase of height.

1879 Cassell's Techn. Educator ii. 106 The various practical operations that are gone through to ascertain how much the parapets should be raised to obtain cover, are called defilade.

1828 J. M. Spearman Brit. Gunner 217 When a work is commanded by a height in front, the interior must be defiladed by elevating the parapet to such a height, that a line of fire from..the hill..may be every where at least eight feet above the terre-plein of the work.

1828 J. M. Spearman Brit. Gunner 218 When a work is commanded in reverse, the parapet or traverse must be high enough to defilade the defenders of the banquette opposite the height.

1830 E. S. N. Campbell Dict. Mil. Sci. at Defilement The operation..called Defilement, or Defilading, is of two kinds, in altitude and in direction.

1851 J. S. Macaulay Treat. Field Fortif. 297 Proof that the defilading operations have been incorrectly executed.