Boot, an instrument consisting of four long strips either of iron or of wood, fastened together, with space between, into a sort of case for the leg. Into the space wedges were inserted, and struck by the executioner with a hammer, so as to crush the leg. It was used in England in the 16th and part of the 17th century. In Scotland it was a familiar instrument in the persecution of the Covenanters by James II., but was finally made illegal on the union with England. It was used to extort confessions or other evidence.