What is "trou-de-loup"

Trou-de-loup \Trou"-de-loup"\, n.; pl. Trous-de-loup. [F. trou hole + de of + loup wolf.] (Mil.) A pit in the form of an inverted cone or pyramid, constructed as an obstacle to the approach of an enemy, and having a pointed stake in the middle. The pits are called also trapholes.

n. A pit in the form of an inverted cone or pyramid, constructed as an obstacle to the approach of an enemy, and having a pointed stake in the middle.

1. n. a sloping pit with a stake in the middle used as an obstacle to the enemy

2. [also: trous-de-loup (pl)]