[Fr. levier.] One of the mechanical powers. It consists of a bar of wood or metal, supported by and movable at some point of its length round a prop, called the fulcrum, while at the other points are placed the weight or resistance to be overcome and the power or force which overcomes it. Levers are divided into three kinds, namely - (I) when the fulcrum is between the weight and the power, as in the crowbar; (2) when the weight is between the power and the fulcrum, as in rowing a boat; (3) when the power is between the weight and the fulcrum, as in raising a ladder from the ground. Bones of animals are levers of the third kind.