The Collaborative International Dictionary
Fougade
Fougade \Fou`gade"\, Fougasse \Fou`gasse"\, n. (Mil.) A small mine, in the form of a well sunk from the surface of the ground, charged with explosive and projectiles. It is made in a position likely to be occupied by the enemy.
Wiktionary
fougade
n. (context military historical English) A kind of land mine; a fougasse.