Defilading

Chambers's Encyclopaedia, Volume 3: Catarrh to Dion, p. 731

Defilading, in Fortification (q.v.), consists in determining the direction and height of the rampart, so that the interior of the work may not be commanded by the fire of the enemy. To prevent the lines being enfiladed, their prolongations must avoid all places where hostile batteries could be posted, and the parapets must be of sufficient height to protect the interior from frontal fire.

Source scan(s): p. 0742