A couple terms I had to learn in Military Medicine many years ago.
defilade
vt., vi.
laded, < Fr d=filade, a filing off, succession < d=filer: see DEFILE26 to arrange (troops and fortifications) so that the terrain will protect them, esp. from gunfire against either flank
n.
1 the act of defilading
2 the protection afforded by defilading

And another related word:
defilade
vt., vi.
laded, < Fr d=filade, a filing off, succession < d=filer: see DEFILE26 to arrange (troops and fortifications) so that the terrain will protect them, esp. from gunfire against either flank
n.
1 the act of defilading
2 the protection afforded by defilading

And also learned in military medicine, but not French
interdictory fire - either artillery or machine gun fire that can prevent enemy from entering
an important part of terrain