trous-de-loup

trous-de-loup

(ˌtruːdəˈluː) n, pl trous-de-loup (ˌtruːdəˈluː) (Fortifications) military any of a series of conical-shaped pits with a stake fixed in the centre, formerly used as protection against enemy cavalry[C18: from French, literally: wolf's holes]