a large piece of timber, pierced, and traversed with wooden pikes, and five or six feet long, armed or pointed with iron. The term is French, and properly signifies a Frisian horse, this term having been applied either from some conceived analogy between the appearance of the shaggy horses of the country and that of the instrument, or because it was first invented in Friseland. Chevaux-de-frise are used to defend a passage, stop a breach, or secure the avenues of a camp against both horse and foot. They are sometimes also mounted on wheels with artificial fires, to roll down in an assault. Chevaux-de-frise were first used at the siege of Groningen in 1658.