(shuh-VAL duh FREEZ)
noun plural chevaux-de-frise (shuh-VOH duh FREEZ)
1. An obstacle, typically made of wood, covered with barbed wire or spikes, used to block the advancing enemy.
2. A line of nails, spikes, or broken glass set on top of a wall or railing to deter intruders. [From French, literally horse of Friesland, so named because it was first used by Frisians who lacked cavalry
Pictures of chevaux-de-frise: civilwarfortifications.com/dictionary/xgc-020.html.
Usage
"Fold back the leaves of an artichoke and you discover ... more artichoke leaves, at least until you come to the succulent, secret heart hidden beneath a chevaux-de-frise of thistle-like bristle." — David Nelson; Gastronomic Adventure Unfolds Like an Artichoke; The Los Angeles Times; Jun 21, 1991.
"On the land side, outside the battlements, are acres of chevaux-de-frise: sharp rock slabs set vertically into the ground, making it virtually impossible for a person to pass, let alone a horse." — Denise Fainberg; On Foot In Inishmore; The New York Times; Aug 1, 1999.