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]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014