a cutting instrument.-an instrument consisting of two blades, commonly with bevel edges, connected by a pivot, and working on both sides of the material to be cut, -- used for cutting cloth and other substances.-a similar instrument the blades of which are extensions of a curved spring, -- used for shearing sheep or skins.-a shearing machine; a blade, or a set of blades, working against a resisting edge.-anything in the form of shears.-a pair of wings.-an apparatus for raising heavy weights, and especially for stepping and unstepping the lower masts of ships. it consists of two or more spars or pieces of timber, fastened together near the top, steadied by a guy or guys, and furnished with the necessary tackle.-the bedpiece of a machine tool, upon which a table or slide rest is secured; as, the shears of a lathe or planer. see illust. under lathe.